Abstract Book of the 2nd General Assembly for the

The Moroccan ISBN Agency ISBN 978-9920-35-173-7

Abstract Book of the 2nd General Assembly for the African Seismological Commission from 23th until 27th of April 2018 Al-Hoceima, Morocco Edited by: Mourabit, T., El Talibi, H., El Moussaoui, S. & El kharki, O.

2018 Al Hoceima African Seismological Commission

Editors: Prof. Taoufik Mourabit Dean Faculty of Sciences and Techniques of Al-Hoceima University of Mohammed Premier, Morocco Email: [email protected]

Prof. Hajar El Talibi Departement of Earth Sciences Faculty of Sciences and Techniques of Al-Hoceima University of Mohammed Premier, Morocco Email: [email protected]

Dr. Said El Moussaoui Department of Earth Sciences Faculty of Sciences and Techniques of Tangier University of Abdelmalek Essaadi, , Morocco Email: [email protected]

Prof. Omar El Kharki Department of Earth Sciences Faculty of Sciences and Techniques of Tangier University of Abdelmalek Essaadi, , Morocco Email: [email protected] @gmail.com

Coyrights: © African Seismological Commission, 2018 © Faculty of Sciences and Techniques of Al Hoceima, 2018 All rights reserved. Legal deposit: 2018MO0824 The Moroccan ISBN Agency ISBN 978-9920-35-173-7

2nd General Assembly for the African Seismological Commission, Al Hoceima 2018

Preface It is a great pleasure to welcome you at the 2nd General Assembly for the African Seismological Commission (2AfSC2018), held in AL Hoceima, Morocco (23-27 April 2018). This volume includes the 135 abstracts accepted for oral (74) and poster (61) presentations. These were dispatched within 8 sessions covering the majority of seismological topics. All abstracts have been reviewed by the 30 co-chairs of the sessions. In addition, plenary conferences have been organized by researchers who have long devoted themselves to geodynamic and geophysical studies in Africa. This Abstract volume, which provides an excellent overview of current research trends in seismology, is a reference platform for researchers interested in seismological studies within Africa to promote multi-sectoral and collaborative scientific projects ranging from seismic monitoring, seismotectonics and, seismic hazard to education and outreach. I would like to express my deep gratitude to the members of the Organizing committee for dedicating so much of their time to the organization of the conference. On behalf of the Organizing Committee, I wish to thank warmly the African Seismological Commission (AfSC) and its Executive Committee for putting their trust in the Moroccan community of seismologists. Collectively, we are all very grateful to : International Association of Seismology and Physics of the Earth's Interior (IASPEI), Kinemetrics, International Union of Geodesy and Geophysics (IUGG), and International Seismological Center (ISC). We appreciate very much the support of Moroccan academic institutions, Université Mohamed Premier (UMP)”, the “Centre National de la Recherche Scientifique et Technique (CNRST), the Scientific Institute (IS) of Mohamed V university, the local authorities and representatives for the crucial help and to all sponsors that have kindly provided financial and logistical support in a difficult economic period. Taoufik MOURABIT Faculty of Sciences and Techniques of Al Hoceima General Chair of 2nd General Assembly for the African Seismological Commission .

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Contents Preface .............................................................................................................................................................. i Contents.......................................................................................................................................................... ii Steering Committee .................................................................................................................................xvii Scientific Committee ............................................................................................................................. xviii Program Overview ...................................................................................................................................... xx Detailed scientific program and index of abstracts ..........................................................................xxi Program Schedule ................................................................................................................................. xxxiv Abstracts ................................................................................................................................................xxxvii Alphabetical Index of Presenting Authors .......................................................................................... 136

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Steering Committee Pr. Taoufik MOURABIT Dean of the Faculty of Sciences and Techniques of Al-Hoceima University of Mohammed Premier, Morocco Email: [email protected] Pr. Mimoun CHOURAK Department of Mecanics and applied mathematic University of Mohammed Premier, Oujda, Morocco Email: [email protected] Pr. Hajar EL TALIBI Departement of Earth Sciences Faculty of Sciences and Techniques of Al-Hoceima Email: [email protected] Pr. Najat Moradi Vice-Dean of Educational Affairs Faculty of Sciences and Techniques of Al-Hoceima Eamail: [email protected] Pr. Hinde CHERKAOUI Head of Departement of Earth Sciences Faculty of Sciences and Techniques of Al-Hoceima Email: [email protected] Pr. Issam ETEBAAI Departement of Earth Sciences Faculty of Sciences and Techniques of Al-Hoceima Email: [email protected] Pr. Abderrahim EL ALLATI Department of Physics Faculty of Sciences and Techniques of Al-Hoceima Email: [email protected] Dr. Said EL MOUSSAOUI Department of Earth Sciences Faculty of Sciences and Techniques of Tangier Email: [email protected]

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Scientific Committee Atalay AYELE Addis Ababa University · Institute of Geophysics, Space Sciences and Astronomy (IGSSA), Ethiopia Mohamed ABED Saad Dahlab University, Blida, Algeria Bekoa ATEBA Institute of Geol. Mining Research, Cameroon Abdelhakim AYADI Centre of Research of Astronomy, Astrophysics and Astrophysics and Geophysics (Algeria) Alaeddine BELFOUL University Ibn Zohr , Agadir, Morocco

Mimoun HARNAFI Mohammed V University of Rabat, Morocco Awad HASSOUP NRIAG-National Research Institute of Astronomy and Geophysics, Egypt Ahmed HOSNY NRIAG-National Research Institute of Astronomy and Geophysics, Egypt Hesham HUSSIEN NRIAG-National Research Institute of Astronomy and Geophysics, Egypt Jesus GALINDO ZALDIVAR University of Granada, Spain

Djillali BENOUAR University of Science and Technology Houari Boumediene, Algeria

Michelle GROBBELAAR CGS- Council for Geoscience , South Africa

Mourad BEZZEGHOUD School of Sciences and Technology, Universidade de Évora, Portugal

Said MAOUCHE Centre of Research of Astronomy, Astrophysics and Geophysics, Algeria

Samir BOUAZIZ ENIS-National School of Engineering, University of Sfax ,Tunisia

Mustapha MEGHRAOUI EOST - Université of Strasbourg, France

Martin Brandt CGS- Council for Geoscience, South Africa Mimoun CHOURAK ENSA - Mohamed I University of Oujda, Morocco Mohamed EL GABRY NRIAG-National Research Institute of Astronomy and Geophysics, Egypt Nacer JABOUR Centre National pour la Recherche Scientifique et Technique, Morocco Zakaria HAMIMI Banha University, Egypt Assia HARBI Centre of Research of Astronomy, Astrophysics and Geophysics , Algeria

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Vunganai MIDZI CGS- Council for Geoscience, South Africa Taoufik MOURABIT FSTH - Mohamed I University of Oujda, Morocco Hatem ODAH NRIAG-National Research Institute of Astronomy and Geophysics, Egypt Antonella PERESAN OGS- National Institute of Oceanography and Experimental Geophysics, Italy Mohammed ROGUI ESTS- Sale, Morocco Abdelhamid ROSSI FSTT - AbdelmalekEssaadi University of Tangier, Morocco


Youssef TIMOULALI Institut Scientifique - University Mohamed V Rabat, Morocco Antonio VILLASENOR Institute of Earth Sciences Jaume Almera, Barcelona Spain Abdelkrim YELLES CHAOUCH CRAAG - Centre of Research of Astronomy, Astrophysics and Geophysics, Algeria Hakim Boulaassal FSTT – Abdelmalek Essaadi University of Tangier, Morocco Khadija Aboumaria FSTT – Abdelmalek Essaadi University of Tangier, Morocco Omar El kharki FSTT – Abdelmalek Essaadi University of Tangier, Morocco Raymond Durrheim School of Geosciences, University of Witwatersrand Johannesburg, South Africa Ahmed Ksentini National Engineers School of Tunis, Tunisia Abdelilah Tahayt Mohammed V University of Rabat, Morocco

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Robert Reilinger Massachusetts Institute of Technology, USA Philippe Vernant

Geoscience Montpellier, France Nadia Mhammdi Mohammed V University of Rabat, Morocco Georges Mavonga Goma Volcanic Observatory, Democratic Republic of Congo Damien Delvaux Royal Museum for Central Africa, Belgium Paulina Amponsah Ghana Atomic Energy Commission, Ghana Magda Roos CGS- Council for Geoscience, South Africa Benaissa Tadili Mohammed V University of Rabat, Morocco Lahsen Ait-Brahim Mohammed V University of Rabat, Morocco Najla Romdane University of Tunis El Manar, Tunisia Fabio Romanelli University of Trieste, Italy

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Program Overview Monday 23 April 2018 08h30 Registration 09h00-10h00 Opening speechs 10h00-10h40 Coffee Break 10h40-12h00 Plenary session 12h00-13h00 Lunch Break 13h00-14h00 Shuttles from Hotel to FSTH (1hour) S01: Active Tectonics, Paleoseismology and Historical Seismicity (Room A) 14h00-16h00 S02 : Seismic source/Induced seismicity (Room B) 16h00- 16h40 Coffee Break/poster session S01: Active Tectonics, Paleoseismology and Historical Seismicity (Room A) 16h40- 18h00 S02 : Seismic source/Induced seismicity (Room B) 18h30- 19h30 UNESCO - IGCP-659 Business and kickoff Meeting Tuesday 24 April 2018 S03: Ground motion and site effects (Room A) 08h40-10h00 S04 : Tsunami hazard : data collection and modelling (Room B) 10h00-10h40 Coffee Break/poster session S03: Ground motion and site effects (Room A) 10h40-12h00 S04 : Tsunami hazard : data collection and modelling (Room B) 12h00-14h00 Lunch Break S05 : Earth structures in Africa/The East African Rift System (Room A) 14h00-16h00 S06 : GIS and Risk Scenario (Room B) 16h00- 16h40 Coffee Break/poster session 16h00- 18h00 AFSC Business meeting 20h30 Conference dinner Wednesday 25 April 2018 S07: Earthquake Hazard Assessment (Room A) 08h40-10h00 S08 : Geodynamics,GPS, InSAR and remote sensing (Room B) 10h00-10h40 Coffee Break/poster session S07: Earthquake Hazard Assessment (Room A) 10h40-12h00 S08 : Geodynamics,GPS, InSAR and remote sensing (Room B) 12h00-14h00 Lunch Break S07: Earthquake Hazard Assessment (Room A) 14h00-16h00 S08 : Geodynamics,GPS, InSAR and remote sensing (Room B) 16h00- 16h40 Coffee Break/poster session 16h40- 18h00 S08 : Geodynamics,GPS, InSAR and remote sensing (Room B) General Discussion and Recommendations (Cloture): 18h00- 19h00 The future of AfSC and the Earthquake Data Centre for Africa Thursday 26 April 2018 09h00-12h00 Practical Training Courses 1: Seismotectonics (Room A) 12h00-14h00 Lunch Break 14h00-18h00 Practical Training Courses 1: Seismotectonics (Room A) Friday 27 April 2018 09h00-12h00 Practical Training Courses 2: Radar interferometry and its applications: 12h00-14h00 Lunch Break 14h00-18h00 Practical Training Courses 2: Radar interferometry and its applications:

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Detailed scientific program and index of abstracts PLENARY SESSION C.01: EARTHQUAKES IN AFRICA: THE SEISMOTECTONIC AND SEISMIC HAZARD PERSPECTIVES...........................................................................................................1 Meghraoui Mustapha (Monday 23 April 2018: 10h40 – 11h10) C.02: GLOBAL POSITIONING SYSTEM (GPS) CONTRIBUTIONS TO ACTIVE TECTONICS IN AND BORDERING AFRICA ...................................................................... 2 Reilinger Robert, King Robert, Floyd Michael et al,. (Monday 23 April 2018: 11h10 – 11h40) C.03: Al Hoceima, The light house of the southern Bank of Western Mediterranean ................... Ben Sari Driss,. (Monday 23 April 2018: 11h40 – 12h10) S.01: ACTIVE TECTONICS, PALEOSEISMOLOGY AND HISTORICAL SEISMICITY S.01O01: RECENT SEISMICITY AND EARTHQUAKE RISK IN ETHIOPIAN CITIES ............ 3 Atalay Ayele (Monday 23 April 2018: 14h00) S.01O02: ACTIVE TECTONICS OF PERU: HETEROGENEOUS INTERSEISMIC COUPLING ALONG THE NAZCA MEGATHRUST, RIGID MOTION OF THE PERUVIAN SLIVER, AND SUBANDEAN SHORTENING ACCOMMODATION ................................................................................................................... 4 Chlieh Mohamed, Villegas Lanza Juan Carlos, Cavalié Olivier et al,. (Monday 23 April 2018: 14h20) S.01O03: PRESENT-DAY SEISMOTECTONICS BENEATH THE RIF-ATLAS AREA, MOROCCO, FROM EARTHQUAKE FOCAL MECHANISM DATA ............................ 5 El Moudnib Lahcen (Monday 23 April 2018: 14h40) S.01O04: GEOLOGY, TECTONIC AND DEEP PROCESS IN THE HOGGAR SWELL (ALGERIA) ...................................................................................................................................... 6 Abdelhakim Ayadi, Meghraoui Mustapha, Said Maouche (Monday 23 April 2018: 15h00) S.01O05: USE OF EARTHQUAKE LOCATIONS TO IDENTIFY SEISMOGENIC STRUCTURES IN THE WITWATERSRAND BASIN, SOUTH AFRICA .................... 7 Myendeki Sinovuyo (Monday 23 April 2018: 15h20) S.01O06: VERY RECENT SEABOTTOM DEFORMATION IN THE AREA AFFECTED BY THE 2016-2017 SEISMIC CRISIS IN THE ALBORAN SEA (WESTERN MEDITERRANEAN) .................................................................................................................... 8 Galindo-Zaldivar Jesus , Ercilla Gemma, Estrada Ferran et al,. (Monday 23 April 2018: 15h40)

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S.01O07: AL HOCEIMA NORTHERN MOROCCO 1994, 2004 AND 2016 SEISMIC SEQUENCES................................................................................................................................... 9 Nacer Jabour (Monday 23 April 2018: 16h40) S.01O08: THE ACTIVE FAULTS OF THE MITIDJA BASIN (NORTH CENTRAL ALGERIA): WHAT DOES THE SEISMIC HISTORY OF THE REGION TELL US? .................................. 10 Maouche Said, Harbi Assia (Monday 23 April 2018: 17h00) S.01O09: THE SEISMITES OF THE PLEISTOCENE FORMATIONS IN THE NORTH-EAST OF RABAT AS AN INDICATOR OF PREHISTORIC EARTHQUAKES AND PROBABLE PRECURSOR OF THE LISBON EARTHQUAKE OF 1755 AD............................11 Lambarki Drissi Ibtissam, Aberkane M'hamed (Monday 23 April 2018: 17h20) S.01O10: REVIEW IN SEISMOTECTONIC SETTING OF GULF OF AQABA WITH RESPECT TO THE 27 JUNE 2015 AND 16 MAY 2016 AQABA EARTHQUAKE SWARMS ........................................................................................................................................ 12 Abdel-Aal Abdel-Aziz, Mostafa Shaimaa (Monday 23 April 2018: 17h40) S.01P01: SEISMICITY AND STRESS FIELD VARIATIONS IN RIF REGION & ALBORAN SEA FROM MAJOR SEISMIC CRISIS : 1960-2016. ...................................... 13 Dahaoui Mohamed, Abdelouafi Abdellah, El Mahsani Abderrahman et al,. (Monday 23 April 2018: Poster session) S.01P02: LA MORPHO-STRUCTURE DES FORMATIONS NEOGENE ET PLIOQUATERNAIRES DU RIF ORIENTAL (MAROC) ............................................................14 Makkaoui Mohamed, Azzouz Omar (Monday 23 April 2018: Poster session) S.01P03: UPDATED SEISMICITY OF BOTSWANA FOR THE PERIOD 1950?2017 ................. 15 Kwadiba Tarzan, Ntibinyane Onkgopotse, Mpuang Admore et al., (Monday 23 April 2018: Poster session) S.01P04: SOFT-SEDIMENT DEFORMATION STRUCTURES INDUCED BY EARTHQUAKES (SEISMITES) IN QUATERNARY DEPOSITS (WESTERN ORAN ,ALGERIA)........................................................................................................................ 16 Guessoum Nabila, Benhammouche Azzeddine, Bouhadad Youcef (Monday 23 April 2018: Poster session) S.01P05: GEOMORPHIC, STRATIGRAPHY AND NEOTECTONICS IN THE HODNA BASIN (ALGERIA): CASE STUDY OF THE CHOTT EL HAMMAM STRUCTURE................................................................................................................................. 17 Ahmed Rezouk, René Guiraud, Bouhadad Youcef et al., (Monday 23 April 2018: Poster session) S.01P06: THE ACHAKKAR QUATERNARY FM. SEISMITES (NORTHERN ATLANTIC COAST, MOROCCO): ARE THEY TRIGGERED BY RECENT SEISMOTECTONICS ACTIVITY ............................................................................................ 18 Benamri Sofia, Aboumaria Khadija, Aberkan M'hamed et al., (Monday 23 April 2018: Poster session) S.01P07: SEISMOTECTONICS MAP OF NORTHERN EGYPT ..................................................... 19 Salama Asem, Meghraoui Mustapha, El Gabry Mohamed et al., (Monday 23 April 2018: Poster session) S.01P08:

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THE SEISMES OF THE SÉTIF REGION, READING AND INTERPRETATION .................................................................................................................... 20 Djenba Samir (Monday 23 April 2018: Poster session)


S.01P09: SEISMICITY AND SEISMOTECTONIC OF THE AREA OF ALGAVRE (PORTUGAL) ............................................................................................................................... 21 Dib Assia, Bezzeghoud Mourad, Abdelhakim Ayadi et al., (Monday 23 April 2018: Poster session) S.01P10: ACTIVE TECTONIC IN MEDITERANEAN COAST: NEW INSIGHTS FOR THE ARZEW SALINES, NORTHWEST ALGERIA..........................................................22 Benbakhti Imene Meriem, Maouche Said, Belhai Djelloul et al., (Monday 23 April 2018: Poster session) S.01P11: L'UTILISATION D'UN IMEL POUR L'ÉTUDE LE MOUVEMENT DE LA FAILLE DE TROUGOUT - NORD EST DU RIF) MAROC) -......................................... 23 Morad Taher, Taoufik Mourabit (Monday 23 April 2018: Poster session) S.02: SEISMIC SOURCE/INDUCED SEISMICITY S.02O01: ASWAN INDUCED SEISMICITY ........................................................................................ 24 Hassoup Awad (Monday 23 April 2018: 14h00) S.02O02: EARTHQUAKE LABORATORIES IN DEEP SOUTH AFRICAN MINES .................25 Durrheim Raymond, Andriamiranto Raveloson, Ogasawara Hiroshi et al., (Monday 23 April 2018: 14h20) S.02O03: SEISMIC REFRACTION AND AMBIENT NOISE H/V SURVEYS TO INVESTIGATE AND REBUILD AN OLD BRIDGE, ACROSS GHIS RIVER LOCATED IN THE SEISMIC AREA OF AL HOCEIMA, NOTH MOROCCO ..........26 El Ouai Driss, Tadili Ben Aissa, Tadili Mehdi (Monday 23 April 2018: 14h40) S.02O04: SEISMIC HAZARD AND NEW SEISMOGENIC ZONING IN THE STRAIT OF GIBRALTAR ........................................................................................................................... 27 Abderrahman Elmahsani, Ait Brahim Lahcen, Tadili Benaissa et al., (Monday 23 April 2018: 15h00) S.02O04: THE 2016 MIHOUB (NORTH-CENTRAL ALGERIA) EARTHQUAKE SEQUENCE: SEISMOLOGICAL AND TECTONIC ASPECTS ......................................28 Khelif Mohamed Fadhlallah, Yelles-Chaouche Abdekrim, Benaissa Zahia (Monday 23 April 2018: 15h20) S.02O06: ASSESSMENT OF TEMPORAL VARIATION AND SPATIAL VARIATION OF RECURRENCE PARAMETERS IN THE GOLD MINING REGIONS OF SOUTH AFRICA ..........................................................................................................................29 Zulu Brian Sibonelo, Midzi Vunganai, Manzunzu Brassnavy et al., (Monday 23 April 2018: 15h40) S.02O07: REASSESSING THE RUPTURE PROCESS OF THE 2003 BOUMERDESZEMMOURI EARTHQUAKE (MW 6.8, NORTHERN ALGERIA) USING TELESEISMIC, STRONG MOTION, INSAR, GPS, AND COASTAL UPLIFT DATA ............................................................................................................................................... 30 Beldjoudi Hamoud, Delouis Bertrand, Yelles Chaouche Abdelkrim et al., (Monday 23 April 2018: 16h40) S.02O08: SPATIAL DISTRIBUTION OF ATTENUATION IN NORTHERN MOROCCO AND THEIR INTERPRETATION .................................................................. 31 Boulanouar Abderrahim, Harnafi Mimoun, Dobrynina Anna et al., (Monday 23 April 2018: 17h00)

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S.02P01: THE 2018, 15 JANUARY EARTHQUAKE, ARRAIOLOS (PORTUGAL, M=4.9): RESULTS FROM THE BROADBAND SEISMIC NETWORK DATA AND MACOSEISMIC SURVEY. ............................................................................................. 32 Caldeira Bento, Araújo A. Alexandre, Borges José et al., (Monday 23 April 2018: Poster session) S.02P02: SÉQUENCE SISMIQUE DE LA RÉGION D'AÏN AZEL (SUD DE SÉTIF ) JANVIER-MAI 2015. ................................................................................................................... 33 Chami Adel, Yelles-Chaouche Abdelkrim, Benaissa Zahia et la., (Monday 23 April 2018: Poster session) S.02P03: BACKGROUND NOISE OF THE ALDEIA DA SERRA REGION, PORTUGAL ? FROM A TEMPORARY BROAD BAND NETWORK .......................... 34 Wachilala Piedade, Borges José, Caldeira Bento (Monday 23 April 2018: Poster session) S.02P04: SOURCE PARAMETERS OF THE MAIN SEISMIC EVENTS IN THE NORTHEAST REGION OF ALGERIA.................................................................................. 35 Abacha Issam, Boulahia Oualid, Yelles-Chaouche Abdelkarim et al., (Monday 23 April 2018: Poster session) S.02P05: A STUDY ON THE RELATION BETWEEN RECENT INDUCED SEISMICITY AND WATER LEVEL IN THE NORTHWESTERN PART OF NASSER LAKE, ASWAN- EGYPT.......................................................................................... 36 Omar Khaled, Dahy Sayed, Al Amin Ezat (Monday 23 April 2018: Poster session) S.02P06: TRACKING SPATIOTEMPORAL VARIATIONS OF GROUND DEFORMATION AND SOURCE PARAMETERS ALONG SLOW CONVERGENT PLATE BOUNDARIES CASE OF FIGURE: NORTHERN MOROCCO (WESTERNMOST MEDITERRANEAN) ....................................................37 Bouskri Ghizlane, Ammar Abdellah, Timoulali Youssef et al., (Monday 23 April 2018: Poster session) S.02P07: SEISMOTECTONIC MAP OF EGYPT ................................................................................. 38 Badreldin Hazem (Monday 23 April 2018: Poster session) S.03: GROUND MOTION AND SITE EFFECTS S.03O01: STRUCTURE OF MITIDJA BASIN FROM HVSR ........................................................... 39 Fontiela Joao, Borges José, Ouyed Merzouk, Bezzeghoud Mourad et al., (Tuesday 24 April 2018: 08h40) S.03O02: TRAIN INDUCED WAVES PROPAGATION IN LAYERED SOIL ............................. 40 Mohammed Touati, Nezha Lamdouar, Ali Essahlaoui (Tuesday 24 April 2018: 09h00) S.03O03: SEISMIC GROUND MOTION AND LAND USE PLANNING FOR THE GREATER ACCRA METROPOLITAN AREA, SOUTHEASTERN GHANA .............41 Amponsah Paulina, Franco Vaccari, Panza Guliano (Tuesday 24 April 2018: 09h20) S.03O04: ESTIMATION OF SHEAR WAVE VELOCITY PROFILES USING MICROTREMOR ARRAY EXPLORATIONS IN ISMAILIA CITY, EGYPT .............. 42 Maklad Mohamed, Elgabry Mohamed, Yokoi Toshiaki et al., (Tuesday 24 April 2018: 09h40)

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S.03O05: LOCAL SITE EFFECTS STUDY BASED ON THE ORKNEY EARTHQUAKE OF 5 AUGUST 2014 .....................................................................................................................43 Mulabisana Thifhelimbilu, Midzi Vunganai (Tuesday 24 April 2018: 10h40) S.03O06: FORMING OF LANDSLIDES AS A CONSEQUENCE OF SEISMIC ACTIVITY IN THE AREA OF BOSNIA AND HERZEGOVINA.................................... 44 Smailhodzic Hrustem (Tuesday 24 April 2018: 11h00) S.03O07: SITE-EFFECTS INVESTIGATION IN THE URBAN AREA OF NADOR TOWN (N-E MOROCCO), USING THE H/V TECHNIQUE ....................................... 45 Chaaraoui Aboubakr, Chourak Mimoun, Peláez Jose (Tuesday 24 April 2018: 11h20) S.03O08: STATIC CORRECTION FOR SEISMIC DATA ACQUIRED FROM BOUJDOUR AND TARFAYA-LAAYOUNE AREAS (SOUTH OF MOROCCO) ................................................................................................................................. 46 Ayad Abderrrahim, Bakkali Saad (Tuesday 24 April 2018: 11h40) S.03P01: SITE-EFFECTS INVESTIGATION IN THE CITY OF CHLEF, ALGERIA, USING EARTHQUAKE AND AMBIENT VIBRATION DATA ...................................... 47 Layadi Khalissa (Tuesday 24 April 2018: Poster session) S.03P02: ATTENUATION OF CODA WAVES IN SOUSS BASIN, MOROCCO ...................... 48 Azguet Roumaissae, Bouskri Ghizlane, Timoulali Youssef et al., (Tuesday 24 April 2018: Poster session) S.03P03:

SOIL AMPLIFICATION FACTORS AT THE SEISMOGRAPHIC NETWORK STATIONS SITES IN MOROCCO FROM SEISMIC AMBIENT NOISE ............................................................................................................................................. 49 El Fellah Younes, Abd El-Aal Abd El-Aziz et al., (Tuesday 24 April 2018: Poster session)

S.04: TSUNAMI HAZARD: DATA COLLECTION AND MODELLING S.04O01: HOW TIDE VARIATIONS CAN AFFECT THE TSUNAMI IMPACT ON A COASTAL AREA? ........................................................................................................................50 El Moussaoui Said, Omira Rachid, El Talibi Hajar et al., (Tuesday 24 April 2018: 08h40) S.04O02: EVIDENCES OF AN EXTREME MARINE INUNDATION EVENT ON RABAT AREA ATLANTIC COAST (MOROCCO) ............................................................ 51 Benamri Sofia, Aboumaria Khadija et al., (Tuesday 24 April 2018: 09h00) S.04O03: THE 1790 ORAN LARGE EARTHQUAKE (IO IX-X MKS) AND ITS IMPACT IN THE ALBORAN SEA: MODELING OF TSUNAMI WAVES AND CONSTRAINT OF SEISMIC SOURCE .................................................................................52 Meghraoui Mustapha, Kariche Jugurtha, Aini Djamel (Tuesday 24 April 2018: 09h20) S.04O04: TSUNAMI DEPOSITS AND HAZARD ALONG NORTH COAST OF EGYPT CORRELATE WITH HISTORICAL EARTHQUAKE RECORDS OF EASTERN MEDITERRANEAN ............................................................................................... 53 Salama Asem, Meghraoui Mustapha, El Gabry Mohamed et al., (Tuesday 24 April 2018: 09h40)

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S.04O05: EVIDENCE OF TSUNIMAGENIC SOURCES ALONG THE ALGERIAN MARGIN ........................................................................................................................................ 54 Kherroubi Abdelaziz, Yelles Chaouche Abdelkrim, Beldjoudi Hamoud (Tuesday 24 April 2018: 10h40) S.04O06: COULD THE DEPOSITS OF HIGH ENERGY ALONG THE IBERIAN AND MOROCCAN COASTS BE RELATED TO TSUNAMIGENIC EARTHQUAKES? ........................................................................................................................ 55 Korchy Hanan, Aberkan M'hamed, Benamri Sofia (Tuesday 24 April 2018: 11h00) S.04O07: TSUNAMI EVACUATION PLAN FOR TANGIER-MOROCCO BASED ON GIS TOOLS .................................................................................................................................... 56 Benchekroun Sabah (Tuesday 24 April 2018: 11h20) S.04P01: CARTOGRAPHIE ET SIMULATION DES RISQUES NATURELS DU LITTORAL MAROCAIN : RÉSULTATS PRÉLIMINAIRES ........................................... 57 Fajri Zainab, Aboumaria Khadija, El Talibi Hajar et al., (Tuesday 24 April 2018: Poster session) S.04P02: EVIDENCES OF AN EXTREME MARINE INUNDATION EVENT ON TANGIER COASTAL PLAIN ( MOROCCAN ATLANTIC COAST) ........................... 58 El Talibi Hajar, El Moussaoui Said, Aboumaria Khadija et al., (Tuesday 24 April 2018: Poster session) S.04P03: THE PALEOTSUNAMI EVIDENCE AT THE LEVEL OF THE RABTA MARINE TERRACE IN THE JIJEL REGION (EAST ALGERIA) ................................. 59 Benhamouche Azzeddine (Tuesday 24 April 2018: Poster session) S.05: EARTH STRUCTURES IN AFRICA/THE EAST AFRICAN RIFT SYSTEM S.05O01: SEISMIC STRUCTURE OF THE SOUTHERN PART OF MADAGASCAR AS REVEALED BY WAVEFORM MODELING ................................................................. 60 Raveloson Andriamiranto, Durrheim Raymond, Rindraharisaona Elisa (Tuesday 24 April 2018: 14h00) S.05O02: THREE DIMENSIONAL TOMOGRAPHIC IMAGE OF THE TRIPLE JUNCTION AREA, NORTHEAST OF EGYPT .................................................................... 61 Faried Ahmad M., Hosny Ahmed, Farouk Mohamed (Tuesday 24 April 2018: 14h20) S.05O03: CONTRIBUTION OF THE RECEIVER FUNCTION METHOD IN THE VALIDATION OF THE SEISMIC DISCONTINUITIES MODEL IN TUNISIAN AREA ........................................................................................................................ 62 Rekik Dhouha, Ksentini Ahmed, Abbes Chedly (Tuesday 24 April 2018: 14h40) S.05O04: THINNING CRUST WITH HIGH VP/VS RATIO BENEATH THE ABOU DABBAB AREA, SOUTHEAST OF EGYPT. ......................................................................... 63 Hosny Ahmed (Tuesday 24 April 2018: 15h00) S.05O05: INVESTIGATION OF THE 2017 BOTSWANA M6.5 EARTHQUAKE AND ITS AFTERSHOCKS ................................................................................................................... 64 Midzi Vunganai, Saunders Ian, Manzunzu Brassnavy et al., (Tuesday 24 April 2018: 15h20)

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S.05P01: RECENT SEISMICITY (2014- 2017) OF THE OKAVANGO DELTA REGION: CONTRIBUTION OF BOTSWANA'S SEISMIC NETWORK ........................................65 Ntibinyane Onkgopotse, Kwadiba Tarzan, Tladi Bruno et al., (Tuesday 24 April 2018: Poster session) S.05P02: ASSESSING CTBTO'S DATA AND PRODUCTS FOR EARTHQUAKES RELOCATION AND IMPROVEMENT OF VELOCITY MODEL IN SUBSAHARAN AFRICAN .................................................................................................................66 Kadiri Umar, Ezomo Friday, Yakubu Tahir (Tuesday 24 April 2018: Poster session) S.05P03: ACTIVE INTRABASIN FAULTING IN THE NORTHERN BASIN OF LAKE MALAWI FROM SEISMIC REFLECTION DATA............................................................. 67 Chindandali Patrick R.n. (Tuesday 24 April 2018: Poster session) S.05P04: PRECISE STUDY OF THE 2009-2010, KARONGA EARTHQUAKE SWARMS .......................................................................................................................................68 Marimira Kwangwari, Shumba Blessing, Mphepo Felix (Tuesday 24 April 2018: Poster session) S.06: GIS AND RISK SCENARIO S.06O01: SEISMIC EVALUATION OF EXISTING RC BUILDINGS IN AL HOCEIMA AND IMZOUREN USING THE SEISMIC INDEX METHOD ........................................69 Cherif Seif Eddine, Chourak Mimoun, Nobuoto Nojima et al., (Tuesday 24 April 2018: 14h00) S.06O02: EVALUATION OF THE FUNCTIONS OF THE WETLAND COMPLEX BAS LOUKKOS BY GIS AND REMOTE SENSING .................................................................... 70 Fathi Badr-Eddine, Afilal Tribak Abdelghani, Wahbi Meriam (Tuesday 24 April 2018: 14h20) S.06O03: STUDY OF THE IMPACT OF THE SPATIAL AND TEMPORAL DISTRIBUTION OF URBAN HEAT ISLANDS USING REMOTE SENSING AND GIS TECHNIQUE IN THE REGION OF NADOR (ORIENTAL RIF, MOROCCO) ...................................................................................................................................71 Tahouri Jad, Sadiki Abdelhamid (Tuesday 24 April 2018: 14h40) S.06O04: CLIMATE CHANGE EFFECT IN AHWAR ESTUARY AREA IN YEMEN DURING (1985 - 2015) ................................................................................................................ 72 Al-Mahfadi Afrah, Dakki Mohamed (Tuesday 24 April 2018: 15h00) S.06O05: COASTAL VULNERABILITY MAPPING USING THE ANALYTICAL HIERARCHICAL PROCESS CASE OF AD-DAKHLA IN SOUTHWESTERN MOROCCO.................................................................................................................................... 73 Hakdaoui Sofia, Emran Anas (Tuesday 24 April 2018: 15h20) S.06O06: MODELING AND SPATIALIZATION OF WATER EROSION ON THE LANDS OF TWO BASINS OF THE WESTERN MOROCCAN RIF............................. 74 Ouallali Abdessalam, Moukchane Mohamed, Aassoumi Habiba (Tuesday 24 April 2018: 15h40) S.06P01: NEOTECTONIC AND SEISMOTECTONIC INVESTIGATION IN SEISMICALLY ACTIVE REGIONS OF TUNISIA: SEISMOGENIC POTENTIALITIES AND SEISMIC HAZARD ASSESSMENT......................................... 75 Bahrouni Nejib, Merzougui Wissem, Maamri Ridha et al., (Tuesday 24 April 2018: Poster session)

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S.06P02: GIS AND GUIDELINES PAP / RAC FOR MAPPING AND MODELLING OF WATER EROSION RISK PROCESSES IN THE WATERSHED OF OUED ZGANE, (MIDDLE ATLAS MOROCCO)............................................................................. 76 Ousmana Habiba, El Hmaidi Abdellah, El Abassi Mourad et al., (Tuesday 24 April 2018: Poster session) S.06P03: MODÉLISATION ET SIMULATION 2D DU RISQUE D'INONDATION DANS LA VILLE DE ZAÏO (MAROC NORD-ORIENTAL) .............................................77 Naiji Zakariae, Lazzar Ayoub, Oujidi Mostafa et al., (Tuesday 24 April 2018: Poster session) S.06P04: CARTOGRAPHY OF SEISMIC HAZARD IN THE PLAIN OF KASSERINE (WESTERN TUNISIA) USING MORPHOMETRIC INDEXES-SEMI AUTOMATED APPROACH..................................................................................................... 78 Chaieb Ali, Rebai Noamen, Bouaziz Samir (Tuesday 24 April 2018: Poster session) S.06P05: LA CINEMATIQUE D'EVOLUTION DU TRAIT DE COTE DU LITTORAL D'EL JADIDA FACE A LA VULNERABILITE...................................................................... 79 Bourhili Amine, Bendahhou Zourarah, El Khalidi Khalid et al., (Tuesday 24 April 2018: Poster session) S.07: EARTHQUAKE HAZARD ASSESSMENT S.07O01: SEISMIC ASSESSMENT OF A CULTURAL HERITAGE STRUCTURE IN CAIRO CONSIDERING THE SCENARIO BASED APPROACH .................................. 80 Hassan Hany, Sayed Mohamed, Romanelli Fabio et al., (Wednesday 25 April 2018: 08h40) S.07O02: RESEARCHING ENGINEERING CAUSES IN 2003 BOUMERDESALGIERS (ALGERIA) EARTHQUAKE DISASTER: A FORENSIC STYLE METHODOLOGY......................................................................................................................... 81 Benouar Djilali (Wednesday 25 April 2018: 09h00) S.07O03: APPLICATION OF CRISIS CODE TO ASSESS THE SEISMIC HAZARD IN THE EASTERN RIF OF MOROCCO .................................................................................... 82 El Mahsani Abderahman, Ait Brahim Lahsen, Rfifi Mohamed et al., (Wednesday 25 April 2018: 09h20) S.07O04: USING GIS TECHNIQUES FOR THE STUDY OF THE EVOLUTION OF EARTHQUAKES IN MOROCCO BETWEEN THE PERIOD FROM 1901 TO 2010 .................................................................................................................................................. 83 Tahouri Ouassim, Dridri Abdallah, Tahouri Jad (Wednesday 25 April 2018: 09h40) S.07O05: TOWARD PROBABILISTIC SEISMIC HAZARD MODEL SELECTION FOR AFRICA ................................................................................................................................ 84 Ksentini Ahmed, Romdhane Najla (Wednesday 25 April 2018: 10h40) S.07O06: NEOTECTONICS AND SEISMOTECTONICS OF THE KIVU RIFT BASIN: IMPLICATIONS FOR SEISMIC HAZARD ASSESSMENT ............................................ 85 Delvaux Damien, Fiama Sylvanos B., Ganza Gloire B et al., (Wednesday 25 April 2018: 11h00) S.07O07: POST-ERUPTIVE SEISMIC ACTIVITY OF MOUNT CAMEROON FOR THE PERIOD 2005-2016 ............................................................................................................ 86 Ateba Bekoa, Mbossi Eddy Ferdinand (Wednesday 25 April 2018: 11h20)

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S.07O08: A FORECASTING MODEL FOR M>5 EARTHQUAKES USING SPATIALLY-SMOOTHED SEISMICITY. APPLICATION FOR THE ALGERIA-MOROCCO REGION. ........................................................................................... 87 Mohamed Hamdache, Jose Pelaez, Karim Yelles-Chaouche (Wednesday 25 April 2018: 11h40) S.07O09: SEISMIC HAZARD ASSESSMENT OF THE DEMOCRATIC REPUBLIC OF CONGO AND SURROUNDING AREAS BASED ON RECENT COMPILED SEISMIC ZONATION SOURCE MODELS .......................................................................... 88 Mavonga Tuluka Georges, Delvaux Damien, Durrheim Raymond (Wednesday 25 April 2018: 14h00) S.07O10: THE AL HOCEIMA EARTHQUAKE SEQUENCE OF 1994, 2004 AND 2016: STRESS TRANSFER AND POROELASTICITY IN THE RIF AND ALBORAN SEA REGION .................................................................................................................................89 Kariche Jugurtha, Meghraoui Mustapha, Timoulali Youssef (Wednesday 25 April 2018: 14h20) S.07O11: SEISMICITY RATE INFERRED FROM GEOLOGY MODEL AND IMPLICATION IN PROBABILISTIC SEISMIC HAZARD ASSESSMENT, THE CASE OF GAFSA FAULT IN SOUTHWESTERN TUNISIA ............................... 90 Athmouni Malak, Ksentini Ahmed, Abbes Chedly (Wednesday 25 April 2018: 14h40) S.07O12: TOWARD A HOMOGENEOUS MOMENT-MAGNITUDE DETERMINATION FOR EARTHQUAKES IN SOUTH AFRICA: ANALYSIS OF UNCERTAINTIES IN MAGNITUDE CONVERSION............................................... 91 Manzunzu Brassnavy, Brandt Martin, Midzi Vunganai et al., (Wednesday 25 April 2018: 15h00) S.07P01: AN OVERVIEW OF: THE PROBABILISTIC SEISMIC HAZARD ASSESSMENT FOR SUDAN AND THE KHARTOUM SEISMICITY ..........................92 El Tahir Nada, Midzi Vunganai (Wednesday 25 April 2018: Poster session) S.07P02: EVALUATION DE L'ALÉA SISMIQUE DE LA RÉGION DE CONSTANTINE (NORD-EST ALGÉRIEN) .......................................................................................................... 93 Hamidatou Mouloud, Mohammdi Yahia, Nassim Hellal (Wednesday 25 April 2018: Poster session) S.07P03: SISMICITE ET RISQUE SISMIQUE AU MAROC ........................................................... 94 Haou Youssef, Serroukh Mostafa, Ouazani Touhami Abdelouahed et al., (Wednesday 25 April 2018: Poster session) S.07P04: IDENTIFICATION DES PARAMÈTRES SISMIQUES RELATIFS AU SOL DE LA RÉGION DU GRAND NADOR ..................................................................................95 Azougay Abdellah, Chaaraoui Aboubakr, Rezqi Halima et al., (Wednesday 25 April 2018: Poster session) S.07P05: SITE EFFECTS, AMPLIFICATION AND SOIL CHARACTERIZATION OF ALGIERS SEISMIC ZONE ........................................................................................................96 Chabane Souhila (Wednesday 25 April 2018: Poster session) S.07P06: PRELIMINARY STUDY OF SEISMIC HAZARD ALONG THE CAMEROON VOLCANIC LINE ......................................................................................................................... 97 Nana Gaelle Vanessa, Tokam Alain-Pierre (Wednesday 25 April 2018: Poster session)

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S.07P07: STRESS CHANGE AND FAULT INTERACTION FROM A TWO CENTURY-LONG EARTHQUAKE SEQUENCE IN THE CENTRAL TELL ATLAS, ALGERIA........................................................................................................................ 98 Kariche Jugurtha, Meghraoui Mustapha, Ayadi Abdelhakim et al., (Wednesday 25 April 2018: Poster session) S.07P08: RAPID EARTHQUAKE DAMAGE ASSESSMENT OF BUILDINGS USING FUZZY LOGIC APPROACH: APPLICATION TO ALGERIAN BUILDINGS ........... 99 Allali Sid Ahmed, Abed Mohamed, Mebarki Ahmed (Wednesday 25 April 2018: Poster session) S.07P09: EVALUATION DES DOMMAGES STRUCTURAUX POST-SÉISMIQUES PAR LES RÉSEAUX DE NEURONES ................................................................................. 100 Noura Hichem, Abed Mohamed, Mebarki Ahmed (Wednesday 25 April 2018: Poster session) S.07P10: VULNERABILITY/DAMAGE CURVES FOR MAJOR CITIES IN SOUTH AFRICA ......................................................................................................................................... 101 Pule Tebogo, Fourie Christoffel, Kijko Andrzej et al., (Wednesday 25 April 2018: Poster session) S.08: GEODYNAMICS, GPS, INSAR AND REMOTE SENSING S.08O01: MAPPING OF LANDSLIDES BY INTERFEROMETRY RADAR CASE OF LANDSLIDES IN TAOUNATE PROVINCE IN NORTHERN MOROCCO............. 102 Said Benchelha, Hassnaa Chennaoui, Mustapha Hakdaoui et al., (Wednesday 25 April 2018: 08h40) S.08O02: POTENTIAL FIELDS INTERPRETATION IN THE NW OF ALGERIA: EVIDENCES OF ACTIVE FAULTS AND UNDERGROUND STRUCTURE. ..........103 Boukerbout Hassina, Abtout Abdeslam, Yelles-Chaouche Abdelkarim et al., (Wednesday 25 April 2018: 09h00) S.08O03: PLIO-QUATERNARY TECTONIC INVERSION EVIDENCED ALONG THE ALGERIAN MARGIN .............................................................................................................. 104 Yelles Abdelkarim, Aidi Chafik, Beslier Marie-Odile et al., (Wednesday 25 April 2018: 09h20) S.08O04: AN INITIATION OF A SUBDUCTION ZONE ALONG THE ALGERIAN MARGIN: WHAT DOES THERMOMECHANICAL MODELING SAY?.................. 105 Hamai Lamine, Yelles-Chaouche Abdelkarim, Petit Carole et al., (Wednesday 25 April 2018: 09h40) S.08O05: ESTIMATION OF VERTICAL MOVEMENTS IN THE RIF MOUNTAINS (MOROCCO) USING PERMANENT GPS MEASUREMENTS, TIDEALTIMETRY AND SEISMICITY........................................................................................... 106 Fatima Ezzahrae Al Makkassi, Tahayt Abdelilah et al., (Wednesday 25 April 2018: 10h40) S.08O06: NEW CONSTRAINTS ON THE NUBIA-EURASIA PLATE BOUNDARY KINEMATICS FROM GPS MEASUREMENTS IN ALGERIA ..................................... 107 Bougrine Amina, Yelles Karim, Calais Eric et al., (Wednesday 25 April 2018: 11h00) S.08O07: ACTIVE TRANSFORM FAULTS IN THE GULF OF GUINEA: INSIGHTS FROM GEOPHYSICAL DATA AND IMPLICATIONS FOR THE SEISMIC HAZARD ASSESSMENT......................................................................................................... 108 Meghraoui Mustapha, Amponsah Paulina, Bernard Paul et al., (Wednesday 25 April 2018: 11h20)

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S.08O08: THE REACTIVATION CLUES OF THE EAST-ALGERIAN MARGIN ................... 109 Bouyahiaoui Boualem, Sage Françoise, Abtout Abdeslam et al., (Wednesday 25 April 2018: 11h40) S.08O09: CURRENT STATE OF UNDERSTANDING OF TECTONICS IN MOROCCO FROM TWO DECADES OF GEODETIC OBSERVATIONS .................110 Tahayt Abdelilah, Reilinger Robert, Floyd Michael et al., (Wednesday 25 April 2018: 14h00) S.08O10: PRESENT-DAY VERTICAL DEFORMATION IN NEW ZELAND FROM TWO DECADES OF GPS DATA ............................................................................................ 111 Fadil Abdelali, Tenzer Robert, Almakkassi Fatimaezzahrae et al., (Wednesday 25 April 2018: 14h20) S.08O11: FUSION SENTINEL-1 SAR WITH SENTINEL-2 OPTICAL TO EVALUATION AND MONITORING THE DYNAMICS OF TERRITORIES ........... 112 Mahyoub Sulaiman, Rhinane Hassan, El Mehdi Monsour et al., (Wednesday 25 April 2018: 14h40) S.08012: MULTISOURCE APPROACH FOR MONITORING SPATIAL POSITION AND MOISTURE/DRYNESS SURFACE INFORMATION OF WATER CAVITIES OF IMLILY SEBKHAT IN SOUTHWESTERN MOROCCO .................... 113 Hakdaoui Sofia, Emran Anas (Wednesday 25 April 2018: 15h00) S.08O13: CONTRIBUTION OF THE THERMAL INFRARED BAND OF LANDSAT SENSORS (TM & ETM+) TO SPATIOTEMPORAL MONITORING OF SURFACE WATER TEMPERATURE ALONG THE AL MASSIRA LAKE BETWEEN 1987 AND 2017 .......................................................................................................114 Aitelghazi Abdellah, Rhinane Hassan, Bensalmia Ahmed (Wednesday 25 April 2018: 15h20) S.08O14: SEISMOTECTONICS OF THE 2017 BOTSWANA EARTHQUAKE (MW 6.5): AN ACTIVE BRANCH OF THE EAST AFRICAN RIFT ........................................ 115 Meghraoui Mustapha, Midzi Vunganai, Mohamed Saleh (Wednesday 25 April 2018: 15h40) S.08015: GEODYNAMIC FRAMEWORK OF THE NORTHERN AFRICAN MARGIN IN TUNISIA : IMPLICATION FOR SEISMOGENIC POTENTIAL ............................. 116 Bouaziz Samir (Wednesday 25 April 2018: 16h40) S.08016: SEISMIC WAVE VELOCITY AND GEODYNAMIC EVOLUTION IN NW OF WEST AFRICAN CRATON : CASE OF THE MOROCCAN MESETA ? ATLAS DOMAIN ......................................................................................................................... 117 Timoulali Youssef, Jabour Nacer (Wednesday 25 April 2018: 17h00) S.08017: CONTRIBUTION OF RADAR SATELLITE IMAGES IN RELIEF STUDYING IN THE PROVINCE OF AL-HOCEIMA............................................................................... 118 Boulaassal Hakim, Annaki Sara, El Kharki Omar (Wednesday 25 April 2018: 17h20) S.08O18: TROPOSPHERIC WATER VAPOR CORRECTION MODEL FOR INSAR USING ENVISAT/ASAR-MERIS DATA............................................................................... 119 Aguemoune Samir, Abdelhakim Ayadi, Belhadj-Aissa Aichouche (Wednesday 25 April 2018: 17h40) S.08P01: ETUDE ANALYTIQUE DES LINÉAMENTS MORPHO-STRUCTURAUX DU RIF CENTRAL (MAROC) ............................................................................................... 120 Moussaoui Siham, Azzouz Omar (Wednesday 25 April 2018: Poster session)

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S.08P02: SEISMIC ANISOTROPY OF NORTH ALGERIA FROM SHEAR-WAVE SPLITTING ANALYSIS ............................................................................................................. 121 Radi Zohir, Yelles-Chaouche Abdelkrim (Wednesday 25 April 2018: Poster session) S.08P03: INTERFEROMETRY SAR ANALYSIS OF AL HOCEIMA (MOROCCO) DEFORMATION DUE TO A 6.3 MW EARTHQUAKES ON THE 25/01/2016 USING SENTINEL-1A IW. ..................................................................................................... 122 Muhire Desire, Yassine Tounsi, Ahmed Siari et al., (Wednesday 25 April 2018: Poster session) S.08P04: USING MAPPING DATA AND REMOTE SENSING TO GENERATE A 1/100 000 SCALE GEOLOGICAL MAP (AGDZ, MOROCCAN ANTI-ATLAS) ................. 123 Elmortaji Nizar, El Kharki Omar, Boulaassal Hakim et al., (Wednesday 25 April 2018: Poster session) S.08P05: APPLICATIONS OF MULTISPECTRAL REMOTE SENSING TECHNIQUES TO UPDATE THE GEOLOGICAL MAP OF ALMAGHRABAH AREA, HAJJAH PROVINCE, YEMEN .................................................. 124 Alnahmi Fuad, Hilali Atika, Rhinane Hassan et al., (Wednesday 25 April 2018: Poster session) S.08P06: IS THE NUBIA PLATE RIGID OR DIVIDED INTO SUB-PLATES? INSIGHTS FROM GEODETIC DATA AND THE SEISMOTECTONIC MAP OF AFRICA ..........................................................................................................................................................125 Mukandila Ngalula Raphael, Masson Frederic, Meghraoui Mustapha (Wednesday 25 April 2018: Poster session) S.08P07: APPORT DES IMAGES SATELLITAIRES ET DES MODÈLES NUMÉRIQUES DE TERRAIN À LA RECONAISSANCE ET LA CARTOGRPHIE DES STRUCTURES NÉOTECTONIQUE AU NE DE L'ALGÉRIE ...................................................................................................................................126 Mohammedi Yahia, Hamidatou Mouloud (Wednesday 25 April 2018: Poster session) S.08P08: LAND USE/LAND COVER IN SAISS PLAIN, USING REMOTE SENSING TECHNIQUES ............................................................................................................................. 127 El Hafyani Mohammed, Essahlaoui Ali, Mohajane Meriame et al., (Wednesday 25 April 2018: Poster session) S.08P09: GEODYNAMIC EVOLUTION OF BOUKAÏS-EL AHMER AREA (NORTH BECHAR, SW ALGERIA) : USING REMOTE SENSING AND FIELD DATA .........128 Chabane Sarah, Amri Kamel, Hamdidouche Rachid (Wednesday 25 April 2018: Poster session) S.08P10: ESTIMATION OF LAND DEFORMATION IN OILFIELDS BY MEANS OF DINSAR, CASE STUDY IN-SALLAH, ALGERIA ............................................................. 129 Smail Tayeb, Abed Mohamed, Fatma Canaslan çomut (Wednesday 25 April 2018: Poster session) S.08P11: MEASURING DEFORMATION DUE TO 2016 NEW ZEALAND MW7.8 EARTHQUAKE BY USING GNSS PRECISE POINT POSITIONING TECHNIQUE ...............................................................................................................................130 Allal Saddam Housseyn, Dekkiche Hichem, Bouguern Abderrahmane (Wednesday 25 April 2018: Poster session)

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S.09: EDUCATION, OUTREACH & COMMUNICATION S.09P01: THE IMPACT OF CLIMATE CHANGES IN THE WATER RESOURCES IN THE PLAIN OF THE GHARB (WESTERN NORTH OF MOROCCO) ..................... 131 El Houyr Said, Kachtali Mohammed (Wednesday 25 April 2018: Poster session) S.09P02: IDENTIFICATION SISMIQUE DE LA STABILITÉ D'UN BÂTIMENT DANS LA MULTI-PHASE NON LINÉAIRE PAR UN SYSTÈME DE CONTREVENTEMENT DE FRP........................................................................................... 132 Taoufik Tbatou, Elyoubi Mohamed (Wednesday 25 April 2018: Poster session) S.09P03: THE EDUCATIONAL SEISMIC STATION PRINCESS LALLA AICHA OF AGADIR ........................................................................................................................................ 133 El Kilali El Hassan, Es-Saady Youssef (Wednesday 25 April 2018: Poster session) S.09P04: INDICATORS IN RISK MANAGEMENT : A FRESH PERSPECTIVE BETWEEN HAZARD ANALYSES AND SOCIETIES' RESPONSES ........................... 134 Ivcevic Ante, Mazurek Hubert, Siame Lionel (Wednesday 25 April 2018: Poster session) S.09P05: CURRENT STATUS OF THE ISC BULLETIN ................................................................ 135 Shumba Blessing (Wednesday 25 April 2018: Poster session)

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Program Schedule Monday 23 April 2018 Room B

Room A 08h30 10h00 10h00 10h40 10h40 11h10 11h10 11h40 11h40 12h10 12h10 14h00

Registration and Opening speech Coffee Break & Poster Session C01 Meghraoui Mustapha C02 Reilinger Robert et al., C03 Bensari Driss Break Session 1 Active Tectonics, Paleoseismology and Historical Seismicity S.01O01 Atalay Ayele S.01O02 Chlieh Mohamed et al., S.01O03 El Moudnib Lahcen S.01O04 Abdelhakim Ayadi et al., S.01O05 Myendeki Sinovuyo S.01O06 Galindo-Zaldivar Jesus et al.,

Session 2 Seismic source/Induced seismicity

14h00 S.02O01 14h20 Hassoup Awad 14h20 S.02O02 14h40 Durrheim Raymond et al., 14h40 S.02O03 15h00 El Ouai Driss et al., 15h00 S.02O04 15h20 Abderrahman Elmahsani et al., 15h20 S.02O05 15h40 Khelif Mohamed Fadhlallah et al., 15h40 S.02O06 16h00 Zulu Brian Sibonelo 16h00 Coffee Break & Poster Session 16h40 16h40 S.01O07 S.02O07 17h00 Nacer Jabour Beldjoudi Hamoud 17h00 S.01O08 S.02O08 17h20 Maouche Said et al., Boulanouar Abderrahim 17h20 S.01O09 17h40 Lambarki Drissi Ibtissam et al, 17h40 S.01O10 18h00 Abdel-Aal Abdel-Aziz, Mostafa Shaimaa 18h30 UNESCO - IGCP-659 Business and kickoff Meeting 20h00

Tuesday 24 April 2018 Room A Session 3 Ground motion and site effects 08h40 09h00 09h00 09h20

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S.03O01 Fontiela Joao et al., S.03O02 Mohammed Touati et al.,

Room B Session 4 Tsunami hazard : data collection and modelling S.04O01 El Moussaoui Said et al., S.04O02 Benamri Sofia et al.,


09h20 09h40 09h40 10h00 10h00 10h40 10h40 11h00 11h00 11h20 11h20 11h40 11h40 12h00 12h00 14h00

14h00 14h20 14h20 14h40 14h40 15h00 15h00 15h20 15h20 15h40 15h40 16h00 16h00 16h40 16h40 19h00

S.03O03 Amponsah Paulina et al., S.03O04 Maklad Mohamed et al.,

S.04O03 Meghraoui Mustapha et al., S.04O04 Salama Asem et al.,

Coffee Break & Poster Session S.03O05 Mulabisana Thifhelimbilu, Midzi Vunganai S.03O06 Smailhodzic Hrustem S.03O07 Chaaraoui Aboubakr et al., S.03O08 Ayad Abderrrahim, Bakkali Saad

S.04O05 Kherroubi Abdelaziz et al., S.04O06 Korchy Hanan et al., S.04O07 Benchekroun Sabah

Break & Poster Session Session 5 Earth structures in Africa/The East African Rift System S.05O01 Raveloson Andriamiranto et al., S.05O02 Faried Ahmad M et al., S.05O03 Rekik Dhouha et al., S.05O04 Hosny Ahmed S.05O05 Midzi Vunganai et al.,

Session 6 GIS and Risk Scenario S.06O01 Cherif Seif Eddine et al., S.06O02 Fathi Badr-Eddine et al., S.06O03 Tahouri Jad et al., S.06O04 Al-Mahfadi Afrah et al., S.06O05 Hakdaoui Sofia, Emran Anas S.06O06 Ouallali Abdessalam et al.,

Coffee Break & Poster Session AfSC Business meeting

Wednesday 25 April 2018 Room A Session 7 Earthquake Hazard Assessment 08h40 09h00 09h00 09h20 09h20 09h40 09h40 10h00 10h00 10h40 10h40 11h00 11h00 11h20 11h20 11h40 11h40 12h00 12h00 14h00

S.07O01 Hassan Hany et al., S.07O02 Benouar Djilali S.07O03 El Mahsani Abderahman et al., S.07O04 Tahouri Ouassim et al.,

Room B Session 8 Geodynamics, GPS, InSAR and remote sensing S.08O01 Said Benchelha et al., S.08O02 Boukerbout Hassina et al., S.08O03 Yelles Abdelkarim et al., S.08O04 Hamai Lamine et al.,

Coffee Break & Poster Session S.07O05 Ksentini Ahmed et al., S.07O06 Delvaux Damien et al., S.07O07 Ateba Bekoa et al., S.07O08 Mohamed Hamdache et al.,

S.08O05 Fatima Ezzahrae Al Makkassi et al., S.08O06 Bougrine Amina et al., S.08O07 Meghraoui Mustapha et al., S.08O08 Bouyahiaoui Boualem et al.,

Break & Poster Session

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14h00 14h20 14h20 14h40 14h40 15h00 15h00 15h20 15h20 15h40 15h40 16h00 16h00 16h40 16h40 17h00 17h00 17h20 17h20 17h40 17h40 18h00 18h00 19h00

S.07O09 Mavonga Tuluka Georges et al., S.07O10 Kariche Jugurtha et al., S.07O11 Athmouni Malak et al., S.07O12 Manzunzu Brassnavy et al.,

S.08O09 Tahayt Abdelilah et al., S.08O10 Fadil Abdelali et al., S.08O11 Mahyoub Sulaiman et al., S.08O12 Hakdaoui Sofia et al., S.08O13 Aitelghazi Abdellah et al., S.08O14 Meghraoui Mustapha et al.,

Coffee Break Poster Session S.08O15 Bouaziz Samir S.08O16 Timoulali Youssef S.08O17 Boulaassal Hakim S.08O18 Aguemoune Samir General Discussion and Recommendations (Cloture): The future of AfSC and the Earthquake Data Centre for Africa

Thursday 26 April 2018 09h00 12h00 12h00 14h00 14h00 18h00

Room A Practical Training Courses 1: Seismotectonics & NDC in a Box Package: Access and Analysis of Waveform IMS Data and IDC Products. Mustapha Meghraoui, Vunganai Midzi, Youssef Timoulali, Abdelhakim Ayadi & IDC/CBT Break Practical Training Courses 1: Seismotectonics & NDC in a Box Package: Access and Analysis of Waveform IMS Data and IDC Products. Mustapha Meghraoui, Vunganai Midzi, Youssef Timoulali, Abdelhakim Ayadi & IDC/CBT

Friday 27 April 2018 09h00 12h00 12h00 14h00 14h00 18h00

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Room A Practical Training Courses 2: Radar interferometry and its applications Omar El Kharki, Hakim Boulaassal Break Practical Training Courses 2: Radar interferometry and its applications Omar El Kharki, Hakim Boulaassal

Abstracts Plenary session Active Tectonics, Paleoseismology and Historical Seismicity

1 3

Seismic source / Seismic source/Induced seismicity

24

Ground motion and site effects

39

Tsunami hazard : data collection and modelling

50

Earth structures in Africa/The East African Rift System

60

GIS and Risk Scenario

69

Hazard Assessment

80

Geodynamics,GPS, InSAR and remote sensing

102

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Conference: Plenary session https://afsc2018.sciencesconf.org/192991/

C.01: EARTHQUAKES IN AFRICA: THE SEISMOTECTONIC AND SEISMIC HAZARD PERSPECTIVES Meghraoui Mustapha 1 1 - Institut de Physique du Globe, CNRS-UMR 7516 (France)

Abstract The African continent was the site of several destructive earthquakes with moment magnitude Mw ?6.5 since the beginning of the 20th century. Some of these earthquakes are shallow and some of them revealed surface faulting with prominent coseismic slip that can be correlated with seismotectonic structures (plate boundaries, rift systems, transform faults and active intraplate regions). Their occurrence in densely populated areas with increase in building plans caused severe damage and significant economic losses in Africa. Among the oldest major seismic events reported in Africa is the 1200 BC Thebes earthquake that destroyed the Memnon Colossi and Amenhotep III temple in the Nile Valley. Other damaging earthquakes such as the 1862 Ghana (Mw 6.6), 1911 Cameroun (Mw 6.0), 1920 Cape Town (Mw 6.2), 1974 Gabon (Mw 6.1), 1983 Guinea (Mw 6.2) and the 2017 Botswana (Mw 6.5) took place in regions usually considered as ?stable? continental interiors. The recently prepared seismotectonic map of Africa displays the main seismically active zones along with their stress and strain distribution, volcanic fields, and crustal and lithospheric structures 1. The seismic hazard and risk assessments in Africa have always been a challenge in the absence of a complete database that includes well located earthquakes, active faulting and strain rates across the continent (2, 3). The difficulty rises in that many regions remain poorly studied. Following the recent increase of seismic and GPS stations, the plans for an Earthquake Data Centre in Africa along with progress in projects such as SEISMOSHAF leave optimistic perspectives for a realistic earthquake hazard and risk assessment in Africa.

Keywords: Seismotectonics, seismic hazard, risk, perspectives

*Corresponding author Meghraoui Mustapha

1

Conference: Plenary session https://afsc2018.sciencesconf.org/192173/

C.02: GLOBAL POSITIONING SYSTEM (GPS) CONTRIBUTIONS TO ACTIVE TECTONICS IN AND BORDERING AFRICA Reilinger Robert 1, King Robert 1, Floyd Michael 1, Tahayt Abdelilah 2, Taoufik Mourabit 3, Ben Sari Driss 4, Barazangi Muawia 5, Vernant Philippe 6, Davila Jose 7, Ogubazgi Ghebrebrhan 8, Vitres Renier 9, Jonsson Sigurjon 9, Mcclusky Simon 10, Koulali Achraf 11, Gomez Francisco 12, Lewi Elias 13, Bendik Rebbeca 14 1 - Massachusetts Institute of Technology (United States), 2 - Université Mohammed V-Agdal (Morocco), 3 - Université Abdelmalek Essaadi (Morocco), 4 - Private citizen (Morocco), 5 - Cornell University (United States), 6 - Géosciences Montpellier (France), 7 Royal Observatory Aramada (Spain), 8 - Eritrean Institute of Technology (Eritrea), 9 - King Abdullah University of Science and Technology (Saudi Arabia), 10 - Research School of Earth Sciences, Australian National University (Australia), 11 - Australia National University (Australia), 12 - University of Missouri-Columbia (United States), 13 - Addis Ababa University (Ethiopia), 14 - University of Montana (United States)

Abstract Since 1994, MIT and a broad group of African, and other international partners have been using the Global Positioning System (GPS) to map and investigate active deformations within and on the borders of the African continent. GPS estimates of Nubia plate motion with respect to (wrt) Eurasia (i.e., Nubia-Eurasia Euler Vector), indicate counterclockwise rotation of Nubia with oblique convergence increasing from ~5 - 7 mm/yr from Gibraltar to Egypt, with internal deformation of Nubia constrained to 3.0) were identified and targeted for field investigations to determine the stress regime.

Keywords: seismogenic

*Corresponding author Myendeki Sinovuyo

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Oral: Active Tectonics, Paleoseismology and Historical Seismicity https://afsc2018.sciencesconf.org/189947/

S.01: VERY RECENT SEABOTTOM DEFORMATION IN THE AREA AFFECTED BY THE 2016-2017 SEISMIC CRISIS IN THE ALBORAN SEA (WESTERN MEDITERRANEAN) Galindo-Zaldivar Jesus 1, Ercilla Gemma 2, Estrada Ferran 2, Catalán Manuel 3, D'acremont Elia Azzouz Omar 5, Casas David 6, Chourak Mimoun 7, Vazquez Juan Tomás 8, Chalouan Ahmed 9, Sanz De Galdeano Carlos 10, Benmakhlouf Mohamed 11, Gorini Christian 4, Alonso Belén 2, Palomino Desiree 8, Rengel Juan 12, Gil Antonio José 13

4,

1 - Dpto. de Geodinamica, Universidad de Granada /Instituto Andaluz de Ciencias de la Tierra, CSIC- Univ. Granada. (Spain), 2 Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (Spain), 3 - Real Instituto y Observatorio de la Armada (Spain), 4 - Institut des Sciences de la Terre de Paris (France), 5 - Université Mohammed Premier (Morocco), 6 - Instituto Geológico y Minero de España (Spain), 7 - Ecole nationale des sciences appliquées Oujda (Morocco), 8 - Instituto Español de Oceanografía (Spain), 9 - Université Mohamed V de Rabat (Morocco), 10 - Instituto Andaluz de Ciencias de la Tierra, CSIC- UGR (Spain), 11 Faculté des Sciences, Université Abdelmalek Essaadi (Morocco), 12 - Instituto Hidrográfico de la Marina (Spain), 13 - Dpto. Ing. Cartográfica, Geodesia y Fotogrametría, CEAC Tierra Universidad de Jaén, (Spain)

Abstract The Alboran Sea (Westernmost Mediterranean) is a Neogene basin located between the Betic and Rif cordilleras that undergoes shortening and orthogonal extension due to the Eurasian-African NW-SE oblique plate convergence. A NNE-SSW broad band of deformation and seismicity affects its central part extending from the northern Rif (Trougout Fault), the Alboran Sea (Al Idrisi Fault), to southern Betics (Balanegra Fault). After the 1993-1994 and 2004 seismic series, a new crisis shocked mainly the southern Alboran Sea in 2016-2017 (main event Mw=6.3, Jan 25). The nearsurface recent seafloor deformation of this area is investigated using seismic profiles, multibeam and gravimeter data, recovered during the INCRISIS cruise. Epicenters grouped into two main branches. The northern WSW-ENE branch parallels the northern face of the Alboran Ridge- Francesc Pagès seamount antiforms and intersects the Al Idrisi Fault. Mass-transport deposits occurred at least since recent times. The southern branch, that crosses the Francesc Pagès seamount and Nekor Basin, consists of a NNE-SSW vertical sinistral deformation zone, with early epicenters of higher magnitude earthquakes located along a narrow band paralleling the 10 km far east Al Idrisi Fault. Nearsurface deformation includes active NW-SE vertical and normal faults, unmapped until now. Later, the epicenter band spreads eastward, reaching the main Al Idrisi Fault characterized by discontinuous active NE-SW vertical fractures. Seismicity and tectonic structures suggest a westwards propagation of deformation and the growth of very recent incipient faults, comprising NNE-SSW sinistral fault zone in depth that is connected upwards with NW-SE vertical and normal faults. This new fault zone is segmented, including 1994 seismicity in coastal area, that propagates 2004 onshore and 2016 offshore. The new insights for the seismic hazard assessment, point to the growth of new faults can produce potential high magnitude earthquakes than already formed faults.

Keywords:

mass transport deposits, earthquakes, fracture development, African plate boundary, Eurasian, active sea bottom deformations *Corresponding author Galindo-Zaldivar Jesus

8


S.01: AL HOCEIMA NORTHERN MOROCCO 1994, 2004 AND 2016 SEISMIC SEQUENCES Nacer Jabour 1 1 - Centre National de la Recherche Scientifique et Technologique (Morocco)

Abstract The earthquakes series associated with the major events that have affected the Al Hoceima region in 1994, 2004 and recently in 2016 are presented here together to show the spatial and temporal dependency of the events. The complexity of the geologic setting both in land and off-shore is governing the source process of the main shocks as well as the spatial distribution of the foreshocks and aftershocks. The foreshocks corresponding to these major shocks show also a different behavior in particular when comparing the 1994 and 2016 events distribution. The aftershocks corresponding to the each major event overlap spatially in a large proportion meaning that the faults systems were either loaded to the rupture limit as indicated by prompt aftershocks or left without triggering for the coming major event. The focal mechanisms obtained from a number of events together with these observations reflect clearly the local variation of the stress regime which is probably due to the complexity of this part of the Maghreb-Iberia plate boundary. The ground motion records obtained from these major events show more the site effects or the local soil conditions as an important parameter in seismic hazard assessment.

Keywords: strong ground motion, aftershocks, main shock, foreshocks

*Corresponding author Nacer Jabour

9


S.01: THE ACTIVE FAULTS OF THE MITIDJA BASIN (NORTH CENTRAL ALGERIA): WHAT DOES THE SEISMIC HISTORY OF THE REGION TELL US? Maouche Said 1, Harbi Assia 1 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria)

Abstract It is very rare in Northern Algeria, which is an active seismic zone that a rupture reaches the surface. This makes difficult the definition of the characteristic parameters of any active fault. In this paper we combine our own field observations with available geological maps, measurements of neotectonic ruptures, geomorphological data, and the results obtained in recent investigations of historical and instrumental seismicity to help comprehend the complexity of the active deformation of the Mitidja basin (MB). Our analyses reveal the tectonic characteristics of the Mitidja basin and indicate that the seismic activity is essentially concentrated along the system of the boundary faults. The general structural shape of the seismogenic Mitidja basin suggests that the southern fault system would mimic the northern fault system and we observe a highest seismicity rate at the junction point of the NW-SE fault and the south thrust faults system.

Keywords: Algeria, Mitidja basin, historical earthquakes, active tectonics

*Corresponding author Harbi Assia

10


S.01: THE SEISMITES OF THE PLEISTOCENE FORMATIONS IN THE NORTH-EAST OF RABAT AS AN INDICATOR OF PREHISTORIC EARTHQUAKES AND PROBABLE PRECURSOR OF THE LISBON EARTHQUAKE OF 1755 AD. Lambarki Drissi Ibtissam 1, Aberkane M'hamed 1 1 - Faculty of sciences Rabat (Morocco)

Abstract Geological phenomena such as tectonics and volcanism, as well as their consequences such as earthquakes, have existed since the dawn of the history of earth, long before the arrival of man and the discovery of seismographs which, currently, record almost instantly every earthquake of our planet. However, nature has its own seismographs which are sediments. Their geological proprieties allow them to record marks left by earthquakes in the form of sedimentary figures that provide information about the occurrences of seismic activities. The geologist calls seismites sedimentary beds marked and disturbed by seismic activity. The appearance of these figures depends as much on the lithological nature of the deposits and their environmental context, as on the strength of the earthquake to modify the organization of the materials during their sedimentation and before their consolidation. Sedimentary paleoseismicity indices are well preserved, particularly in lacustrine deposits, making it possible to locate and estimate prehistoric and historical paleoseisms (Pascua, 2004). In the coastal area of the Moroccan Atlantic coast north-east of Rabat, Quaternary formations recorded a diversity of seismic figures. For example, those marked in marine, lagoon and dune deposits belonging to the Pleistocene (dated 220ka to 110 ka BP).These records indicate seismic activity of magnitude on the order of 7 on the Richter scale, which could be attributed to prehistoric earthquakes and considered as distant precursors of historical catastrophic earthquakes that affected the Atlantic Iberian and Moroccan fringe, such as the Lisbon earthquake of 1755 and that of 1969 AD. A precise cartography of the distribution of these seismites would contribute to the comparison between prehistoric, historical and current seismicity maps and elaborate database of the evolution of regional seismicity to aid in the assessment of the seism hazard, and takes preceding measures in the prospects of a possible seismic risk prediction.

Keywords:

Earthquakes, seismites, paleoseismicity, precursors, Lisbon earthquake, Quaternary, Atlantic coast, Morocco.

*Corresponding author Lambarki Drissi Ibtissam

11


S.01: REVIEW IN SEISMOTECTONIC SETTING OF GULF OF AQABA WITH RESPECT TO THE 27 JUNE 2015 AND 16 MAY 2016 AQABA EARTHQUAKE SWARMS Abdel-Aal Abdel-Aziz 1, Mostafa Shaimaa 2 1 - National Research Institute of Astronomy and Geophysics (Egypt), 2 - Zagazig University, Faculty of Science, Geology Department, (Egypt)

Abstract In this manuscript, we review recent seismicity and seismotectonic setting of Gulf of Aqaba, based on two recently significant swarms occurred on 27 June 2015 and 22 May 2016. Seismologically, the Gulf of Aqaba is one of the most active places around Egypt, where several earthquake swarms have occurred through ancient and modern times. In the last century, five earthquake swarms of 1983, 1990, 1993 and 1995 have been instrumentally recorded. Recently, on 27 June 2015 a swarm of 96 earthquakes with local magnitudes ranging from 0.7 to 5.2 were recorded by the Egyptian National Seismological Network (ENSN). On 16 May 2016 another swarm started and continued for several consecutive days, and approximately 99 events with local magnitudes ranging from 0.5 to 4.9 .was instrumentally recorded in the gulf south of 27 June 2015 swarm. The complete waveform and polarity data set of both two swarms recorded by the broadband and short period stations of ENSN were essentially analysed to determine type and geometry of faults and to update our knowledge in stress field of and the tectonic setting of Gulf of Aqaba. Through the obtained results, we were able to divide the Gulf of Aqaba tectonically into several segments each segment having different seismic characteristics than the other. The scientific truth that gathers all the gulf segments is that the fault segments are of a kind left lateral strike slip with minor normal component in some segments and minor reverse component in the other.

Keywords: Seismotectonic setting, earthquake swarms, Gulf of Aqaba, Egyptian National Seismological Network (ENSN)

*Corresponding author Abdel-Aal Abdel-Aziz

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Poster: Active Tectonics, Paleoseismology and Historical Seismicity https://afsc2018.sciencesconf.org/192998/

S.01: SEISMICITY AND STRESS FIELD VARIATIONS IN RIF REGION & ALBORAN SEA FROM MAJOR SEISMIC CRISIS : 1960-2016. Dahaoui Mohamed 1, Abdelouafi Abdellah 1, El Mahsani Abderrahman 1, Labraimi Ayoub 1 1 - Université Mohammed V (Morocco)

Abstract This study is devoted to the analysis of the stress state along the Rif and the Alboran Sea region based on the inversion of focal solutions. For this reason, we have constructed a focals mechanisms solutions database containing 131 solutions. Part of it consist of a compilation of focal solutions built from Pwave polarities from available studies, by inversion of broadband seismograms, and CMT solutions. We have constructed the remaining by processing the first P-arrival onsets of aftershocks following large earthquakes, recorded and located by dense temporary seismic networks (Al Hoceima & Alboran Sea). These sequences of aftershocks cover distinct seismogenic zones along the study area and are consequently convenient for establish the stress field and its variation. The stress regime is generally strike-slip in the Moroccan Rift. At the level of the Alboran Sea, The focal mechanisms determined correspond to a strike-slip/normal/reverse motion in the western cluster and thrusting in the eastern one. Locally in Al Hoceima region, the most mechanisms correspond to normal and/or strike-slip faulting mainly. Shows that the main compressional axis.

Keywords:

Stress tensor., Seismicity, Focal mechanism, Al Hoceima, Rif, Alboran sea,

Morocco

*Corresponding author Dahaoui Mohamed

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S.01: LA MORPHO-STRUCTURE DES FORMATIONS NEOGENE ET PLIO-QUATERNAIRES DU RIF ORIENTAL (MAROC) Makkaoui Mohamed 1, Azzouz Omar 2

Abstract Le Rif oriental est marqué par la présence de plusieurs bassins néogènes et plio-quaternaires cadrés par des terrains du mésozoïques qui se trouvent dans des zones en reliefs. Cette disposition s'inscrit dans des structurations en horsts et grabens relevant d'une succession de plusieurs phases de déformations tardi-orogéniques. Elle est déterminée par des déformations essentiellement cassantes animées par des recoupements complexes de plusieurs accidents régionaux. Cette étude a pour objectif de mettre en relief les limites géométriques de ces différents bassins et les mécanismes tectoniques qui ont régi leur différenciation, sur la base de l'apport des données de la cartographie numérique. Dans cette approche, nous avons procédé par une numérisation systématique des cartes géologiques et leur intégration dans un système d'informations géographique. Nous avons défini ainsi une superposition de plusieurs linéaments structuraux coïncidant avec les limites cartographiques des différentes formations néogènes et plio-quaternaires. Ces données ont été confrontées d'une part avec les linéaments majeurs définis par les ruptures morphologiques des reliefs, les réseaux hydrographiques et les traits de côtes. Elles ont été coïncidé d'autres part avec les représentions tridimensionnelles des données sismiques. Ce qui nous permet de vérifier l'ordre chronologique des différentes phases de recoupements et de superposition de ces structurations tectoniques récentes et actives.

Keywords:

Bassin néogène, Cartographie numérique, Tectonique récente et active, Rif oriental, Maroc.

*Corresponding author Makkaoui Mohamed

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S.01: UPDATED SEISMICITY OF BOTSWANA FOR THE PERIOD 1950?2017 Kwadiba Tarzan 1, Ntibinyane Onkgopotse 1, Mpuang Admore 1, Maritinkole Joseph 1 1 - Botswana Geoscience Institute (Botswana),

Abstract Although Botswana is considered to be seismically quiet as it is located thousands of kilometres away from seismogenic tectonic plate boundaries in the surrounding oceans, a major earthquake could still occur under a heavily developed and populated area in the country. For example, Botswana and much of southern Africa were flummoxed by a magnitude 6.5 earthquake on the 3rd April 2017 that nucleated within the heart of the Kgalagadi Desert. Had this event occurred beneath Gaborone, Francistown or any of the densely populated areas of the country, the impact would have been unthinkably catastrophic. Therefore, it is necessary to carry out long-term monitoring of earthquakes to understand the spatial and temporal distribution of the local and regional seismicity, and to contribute in the assessment and mitigation of seismic hazards for the minimization of loss of human life, property damage, and social and economic disruption associated with the occurrence of earthquakes in Botswana and the surrounding area. To that end, an updated earthquake catalogue based on instrumental observations has been assembled for Botswana and the adjacent regions for the period 1950 and 2017. The target region is located within the area delineated by South Latitudes 17o and 28o and East Longitudes 19o and 30o. A better definition of the seismicity of Botswana is currently being achieved through deployment of a network of 21 state-ofthe-art 3C broadband seismographic stations distributed across Botswana. The new stations comprise the Network of Autonomously Recording Stations (NARS)-Botswana project, which is being undertaken jointly by the Botswana Geoscience Institute and the Netherlands based University of Twente and Utrecht University over the period 2013-2018. The collaborative network will revitalize the use of earthquake seismology to investigate the earth structure beneath Botswana and to improve our knowledge the complex tectonics and seismicity regime in southern Africa.

Keywords:

Seismicity, Earthquakes in Botswana, Mitigation of seismic hazards, Instrumental observations

*Corresponding author Kwadiba Tarzan

15


S.01: SOFT-SEDIMENT DEFORMATION STRUCTURES INDUCED BY EARTHQUAKES (SEISMITES) IN QUATERNARY DEPOSITS (WESTERN ORAN ,ALGERIA) Guessoum Nabila 1, Benhammouche Azzeddine 1, Bouhadad Youcef 1 1 - Centre National De Recherche Appliquée En Génie Parasismique (Algeria)

Abstract Western Oranie, is located in the Northwestern of Algeria, is the seat of a seismic activity where several earthquakes were occurred in the past. In this region, several deformation structures in soft sediments have been identified in Quaternary (Villafranchian to present) deposits. The Pleistocene marine terraces contain many Soft- sediment deformation structures (SSDS), mainly located a along the coast and even in the interior of the continent and also found in recent alluvium composed by sandy, silty and clayey sediments. Several outcrop sites have been encountered in this region. The Soft-Sediment Deformation Structures include: injection sand dykes, pillar structures, pillow structures, load-casts structures, water escape structures, sismoslump, thixotropic wedges and thixotropic bowls, all indicative of sediment liquefaction or fluidization. Many arguments supports their seismic origin , the presence of active faults able of producing strong earthquakes, the granulometric characteristics of the deposits are favorable to liquefaction and the observed features. Regional considerations favour that a recent tectonic activity were occurred in this area of Northwestern of Algeria as cause of the soft-sediment deformation structures.

Keywords:

western Oranie, Quaternary deposits, earthquake, seismites, sediment deformation, Soft, Algeria

*Corresponding author Guessoum Nabila

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S.01: GEOMORPHIC, STRATIGRAPHY AND NEOTECTONICS IN THE HODNA BASIN (ALGERIA): CASE STUDY OF THE CHOTT EL HAMMAM STRUCTURE Ahmed Rezouk 1, René Guiraud 2, Bouhadad Youcef 3, Jean François Ritz 4, Belhai Djelloul 5, Maouche Said 6, Kamel Amri 1 1 - Université des Sciences et de la Technologie Houari Boumediene [Alger] (Algeria), 2 - Geoscience Montpellier, Université Montpellier II (France), 3 - Youcef (Algeria), 4 - Geoscience Montpellier, Université Montpellier II, CNRS, UMR 5243 (France), 5 Université des Sciences et de la Technologie Houari Boumedien, Laboratoire de Géodynamique, Géologie de l'Ingénieur et Planétologie (Algeria), 6 - Centre de Recherche en Astronomie, Astrophysique et Géophysique (Algeria)

Abstract The studied area is located in the Hodna Neogene basin in the eastern Tell Atlas of Algeria. From a geological point of view, the Chott El Hammam consists of an ENE-WSW anticline. The folded series range from the Miocene to the Pliocene and are unconformably covered by alluvial terraces and Quaternary limestone encrusting on both sides. This work is two folds: 1)Performing a detailed map of the Miocene, Pliocene and Quaternary alluvial terraces and abandoned Quaternary surfaces; 2) Drawing topographical and geological cross-sections to determine the overall distribution of the morphological and lithological features in the studied area. For this purpose, a database was created to store the different kind of information (topographic maps, a Digital Elevation Model data of 30m and field structural and geomorphic measurements). The combination of different analyses (topographic, geologic, geomorphic) allowed us to constrain the Chott El Hammam fault and related folding and discuss the seismic activity of the studied area.

Keywords: Geomorphic, neotectonics, Hodna basin, Chott El Hammam

*Corresponding author Ahmed Rezouk

17


S.01: THE ACHAKKAR QUATERNARY FM. SEISMITES (NORTHERN ATLANTIC COAST, MOROCCO): ARE THEY TRIGGERED BY RECENT SEISMOTECTONICS ACTIVITY Benamri Sofia 1, Aboumaria Khadija 1, Aberkan M'hamed 2, Zaghloul Mohamed Najib 1 1 - Faculté des Sciences et Techniques de Tanger (Morocco), 2 - Faculty of Science Rabat (Morocco)

Abstract The establishment of Quaternary deposits of the Tangiers peninsula, located at the north-western of the Rif chain, is controlled by a differential neotectonic essentially characterized by vertical movements of pliocene-quaternary age (Morel et al., 1987). The main factors triggering the syn- and late sedimentary structures recorded in the quaternary sediments of the Achakkar Formation and their relative interpretations can be the subject of several controversies (Aboumaria, 2009 ) namely: 1) a controlled liquefaction by the water content in sediments still loose during their gravitational sliding along an underwater slope. This will be at the origin of syn-sedimentary faults, hydroplastic folds, slymps / convolutes and "kelvin-Helmotz" type structures. 2) The gravitational process responsible for the entrainment of liquefied particles and the subsequent deformation of sediments would be triggered by a Seismicity probably related to earthquake and / or energy release along supra-structural fault planes during their tectonic activity.

Keywords: Neotectonics, Seismites., Sedimentary structures, Tangier Peninsula, Quaternary

*Corresponding author Benamri Sofia

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S.01: SEISMOTECTONICS MAP OF NORTHERN EGYPT Salama Asem 1, Meghraoui Mustapha 2, El Gabry Mohamed 1, Hussein Hesham 1, Korrat Ibrahim 3, Maouche Said 4 1 - NRIAG (Egypt), 2 - Institut de Physique du Globe (France), 3 - Mansoura University (Egypt), 4 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria)

Abstract Seismotectonics study was investigated along the northern Egypt. Seismotectonoics map of northern Egypt are built up as first step of construction of seismotectonics map of Egypt. The geology, geomorphology, historical and instrumental seismicity, focal mechanisms, calculated stress inversion, and GPS data were used to identify the present day stress regime of the main active zones. The parameters of the present day stress tensor deduced from focal mechanisms data are calculated using the Tensor program version 5.8.6 of 23 November 2016 for the main six active zones. This method used as the Right Dihedron method and the Rotational Optimization method. The Rotational Optimization method has used in the determination of the four stress parameters, ?1, ?2, ?3 and stress ratio R = (?2 - ?3)/(?l - ?3); used the stress Tensor program to calculate these parameters (Delvaux and Sperner,1993). The main result is that the whole northern Egypt is considered as a part of the extensional regime except the Egyptian continental margin. 3 Layers of GIS database were constructed for the seismotectonics map of north Egypt using geology, geomorphology, historical and instrumental seismicity, focal mechanisms, calculated stress inversion, and GPS data.

Keywords: seismotectonics, active zones, northern Egypt, GIS database

*Corresponding author Salama Asem ,

19


S.01: THE SEISMES OF THE SÉTIF REGION, READING AND INTERPRETATION Djenba Samir 1 1 - universite de batna (Algeria)

Abstract La région de Sétif appartient, selon le RPA 2009, à une zone de moyenne sismicité. Historiquement cette région est frappée par plusieurs séismes de faible à fortes magnitudes (Les séismes de Tizi N'béchar 1924, Kherrata 1949, 1959 ; Ras El Oued 1953 ; Sétif1957 ; Maouan1958 ; Bir Hadada 1963,1968; El Mahdia 1967 ; El Ouricia 1975 ; Djemila avril-juin 1977 ; d'El Madher 1986 et Beni Ourtilène 2000). Les épicentres de ces séismes montrent une harmonie quasi parfaite avec les jeux de failles et aux contacts anormaux des nappes de charriage. Nous essayerons dans ce modeste travail faire une approche séismotectonique afin de relier ces séismes au contexte tectonique de la région et les régions limitrophes. Apriori on constate une nette jonction des épicentres aux contactes anormaux de dj.Youssef - dj Tella et celui des monts de Belezma. Un autre alignement des épicentres est observé le long d'Oued Bouselem de direction NW-SE qui laisse supposer une relation étroite de la sismicité de la région de Sétif avec le décrochement de dj.Bouarif plus au Sud (Nord Est de la ville de Batna). c'est approche basée sur la superposition des foyers des seismes sur les cartes et coupes géologiques compléte par des mesures des structures tectoniques actives sur le terrain.

Keywords: djebel Tella, siesme, Sétif, séisme, djebel Youssef

*Corresponding author Djenba Samir

20


S.01: SEISMICITY AND SEISMOTECTONIC OF THE AREA OF ALGAVRE (PORTUGAL) Dib Assia 1, Bezzeghoud Mourad 2, Abdelhakim Ayadi 3, Mohamed Hamoudi 1 4, Oussadou Farida 3 1 - Université des Sciences et de la Technologie Houari Boumediene [Alger] (Algeria), 2 - Universidade de Évora Colégio Luís António Verney (Portugal), 3 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria), 4 - USTHB (Algeria)

Abstract As part of this thesis, it comes to study the area of Algavre (South of Portugal) by microseismicity campaign in the context of the collision of African and Eurasian plates. This region has generated particular interest because it lies on the border of two tectonic plates which collide with an onshore and offshore seismicity. This study was carried out through a cooperation project between the University of Strasbourg (France) and the University of Evora (Portgal). The stations used and the financing of this campaign belong to the University of Strasbourg and the Portuguese telemetric monitoring network. In this study, there will be to do: data processing for more than a year and a half (seismic data obtained from two monitoring networks, the laptop and the other telemetric). Then, the picking phase, the construction of focal Mechanisms, location and relocation as well as seismic tomography for the determination of the velocity structure at the crust by inversion.

Keywords: Seismicity, tomography, location, tectonic

*Corresponding author Dib Assia

21


S.01: ACTIVE TECTONIC IN MEDITERANEAN COAST: NEW INSIGHTS FOR THE ARZEW SALINES, NORTHWEST ALGERIA Benbakhti Imene Meriem 1, Maouche Said 2, Belhai Djelloul 3, Ritz Jean-François 4, Rabaï Ghilles 3 1 - Université des Sciences et de la Technologie Houari Boumedien, Laboratoire de Géodynamique, Géologie de l'Ingénieur et Planétologie (Algeria), 2 - Centre de Recherche en Astronomie, Astrophysique et Géophysique (Algeria), 3 - Université des Sciences et de la Technologie Houari Boumedien, Laboratoire de Géodynamique, Géologie de l'Ingénieur et Planétologie (Algeria), 4 Géoscience Montpellier CNRS, Université Montpellier (France)

Abstract The Tell Atlas trending belt is one of the most seismically active region in Northern Africa. Located in the western Mediterranean area, along the Africa?Eurasia convergent plate boundary, the Algerian coast displays evidences of active thrusting and coastal uplift associated with large earthquakes. The Mw 6.9, 21 May 2003 Zemmouri and Mw 7.3, 10 October 1980 El Asnam earthquakes were among the strongest events recorded in the area. The Oran basin, located in Northwest Algeria extends from Aïn Temouchent to Mostaganem, experiences a low to moderate seismicity. In this study, we focus on the Salines d'Arzew coastal area, which shows similitudes with seismogenic structures in northern Algeria (i.e Oued Fodda fault (ElAsnam) and the Sahel fold and related reverse fault near Algiers). The geological structures of Arzew Salines correspond to folds and reverse faults, affecting the quaternary formations. Although occurrences of obvious surface breaks have not been shown so far, morphotectonics features provide evidences of cumulative vertical movements associated with NW-SE shortening. They correspond to tilted deposits, and uplifted marine and/or alluvial terraces. These morphological features provide a reference and chronological data to constrain the coastal active tectonics in the Oran-Arzew region.

Keywords: NW Algeria, Arzew Salines, Active tectonics, Coastal zone

*Corresponding author Benbakhti Imene Meriem

22


S.01: L'UTILISATION D'UN IMEL POUR L'ÉTUDE LE MOUVEMENT DE LA FAILLE DE TROUGOUT - NORD EST DU RIF) MAROC) Morad Taher 1, Taoufik Mourabit 1 1 - Université Abdelmalek Essaadi (Morocco)

Abstract A cause du risque sismique que connaît la région d'Al-Hoceima, de nombreuses études ont effectuées dans l'objectif de comprendre la sismicité, la sismotectonique et la géologie structurale, surtout après les derniers séismes de 1994 (Mw=5,4), de 2004 (Mw=6,3) et de 2016 (Mw=6,1). Pour améliorer l'évaluation du risque sismique et préciser la cartographie des failles actives qui affectent la région, diverses techniques et méthodes doivent être utilisées. Nous proposons l'utilisation d'un IMEL pour étudier et suivre le mouvement de la faille active de Trougout. Après quelques mois d'observation, les résultats ne sont pas encore significatifs et nous nous limiterons ici à la présentation de la méthodologie et l'état des lieux de la faille de Trougout.

Keywords: Faille deTrougout, IMEL, mesure le mouvement.

*Corresponding author Morad Taher

23

Oral: Seismic source / Induced seismicity https://afsc2018.sciencesconf.org/199699/

S.02: ASWAN INDUCED SEISMICITY Hassoup Awad 1 1 - National Research Institute of Astronomy and Geophysics [Helwan] (Egypt)

Abstract The Aswan High Dam created the second man-made reservoir in the world (Lake Nasser) and is constructed near urban areas pose a high-risk potential for downstream life and property. It is located in an area occupied by faults dominant in the east?west and north?south trends. This area is seismically active in two seismic zones shallow and deep (i.e. between 0 and 14 and 14 and 30 km), respectively. They are characterized by different b-value, lateral extent and rate of seismicity as well as, spatial clustering. The temporal variation of this seismicity is correlated with the water level fluctuations in the lake. Moreover, it is swarm sequences. The effect of the North African drought (1982 to present) is clearly seen in the reservoir water level. As it decreased and left the most active fault segments uncovered, the shallow activity was found to be more sensitive to rapid discharging than to the filling. This study indicates that geology, lineations in seismicity, offsets in the faults, changes in fault trends and focal mechanisms are closely related. The peak ground acceleration is estimated in the dam site based on strong ground motion simulation. Recently, many moderated earthquake took place nearby the structure of the High Dam. This suggests that AHD dam must be analyzed with high priority and redesigned to increase the safety of the embankments and their appurtenant structures, if necessary.

Keywords: Induced Seismicity, Aswan, Egypt

*Corresponding author Hassoup Awad

24


S.02: EARTHQUAKE LABORATORIES IN DEEP SOUTH AFRICAN MINES Durrheim Raymond 1, Andriamiranto Raveloson 1 , Ogasawara Hiroshi 2, Manzi Musa 3, Yabe Yasuo 4, Onstott Tullis 5, Ziegler Martin 6, Ito Takatoshi 4, Liebenberg Bennie 7 1 - University of the Witwatersrand [Johannesburg] (South Africa), 2 - Ritsumeikan University (Japan), 3 - University of the Witwatersrand (South Africa), 4 - Tohoku University (Japan), 5 - Princeton Univesity (United States), 6 - ETH (Switzerland), 7 Consultant (South Africa)

Abstract It is extremely difficult to investigate the seismogenic zones of large earthquakes directly as they are often several kilometres deep and suitable drilling sites are rarely available. Consequently, there are many questions related to earthquake nucleation and rupture that remain unanswered. Some of the most important knowledge gaps are listed in the ICDP Scientific Plan (2014-2019). These include: (i) the physical properties that control rupture evolution and termination; (ii) the variation with time in physical properties in seismogenic zones and surroundings; (iii) the structural and physical differences between differently-sized earthquakes; and (iv) the fluid and chemical properties of faulting that influence microbiological communities. We also seek to explain the mechanism of the M5.5 Orkney earthquake, which took place on unknown geological structure below the mining horizon with a mechanism markedly different to typical mining-induced earthquakes. In 2017 we commenced an ICDP-funded project (DSeis) to drill into the source zones of M2.0-M5.5 earthquakes located 1-4 km below the surface in four deep South African gold mines. The drilling targets were previously characterised by a Japanese - South African collaborative research project (2009-2015). Cores with a total length of about 1.9 km have already been recovered, with minimal drilling-induced damage. We expect to complete the last ICDP-funded hole in March 2018. It will intersect the aftershock zone of a M5.5 earthquake beneath Moab Khotsong mine. Water and gas will be sampled in order to investigate whether deep microbial life is associated with seismic activity in any way. The DSeis cores are being logged, imaged, and catalogued using the ICDP DIS system. Stress is measured by analysing elastic anisotropic deformation of cores following drilling. Borehole geophysical logs and surface seismic reflection data are also available. A workshop will be held in late 2018 to determine the best rupture model for the M5.5 earthquake.

Keywords: earthquake, induced, gold mine, South Africa, rupture

*Corresponding author Andriamiranto Raveloson

25


S.02: SEISMIC REFRACTION AND AMBIENT NOISE H/V SURVEYS TO INVESTIGATE AND REBUILD AN OLD BRIDGE, ACROSS GHIS RIVER LOCATED IN THE SEISMIC AREA OF AL HOCEIMA, NOTH MOROCCO El Ouai Driss 1, Tadili Ben Aissa 2, Tadili Mehdi 2 1 - Laboratory of Geophysics and Natural Hazards, GEOPAC, Institut Scientifique, Université Mohammed V de Rabat (Morocco), 2 - Iservice Pro (Morocco)

Abstract In this work, we investigate the geotechnical conditions to rebuild an old bridge, located in north of Morocco. This country is considered to be in a region with moderate seismicity. However, the country had suffered in the past from a couple of hazardous events (e.g., Agadir earthquake in 1960, and Al Hoceima one, 2004). The study area is located of about 40 km south of Al Hoceima city (north of Morocco). The aim of this work is to help the local authority decision makers to define technical specifications to rebuild a new bridge across Oued Ghis, replacing the old one with standard norms. Two geophysical surveys (seismic refraction profiling and ambient noise H/V ratios analyses) were carried out simultaneously in April 2017. Results from Refraction show profiles with three layers. 1 An upper layer with a low velocity (218 m/s) formed by loose lime-soil, with a maximum depth of 2.5 m, 2 a medium layer composed mainly by unconsolidated coarse conglomerate, with a velocity of 1187 m/s and a thickness varying laterally, with a maximum depth of about 14 m, and 3 a third layer, with the highest velocity (4124 m/s), representing the bed rocks. It is constituted by an alternation of green shales and sandstone, trending WNW-ESE, and dipping of 34° to 64° North-west. For results from ambient noise H/V ratios, they show that the dominant frequency of the site is about 4 Hz. This increases towards the north of the study area. With these results from refraction and ambient noise H/V ratios, we would recommend that pillars of the new bridge should have a height superior than the maximum thickness (14 m) of the loose layers (1&2). It is also worth to mention that construction should avoid sites to the north, where frequencies start to increase significantly.

Keywords: Seismic refraction, Ambient noise H/V, Oued Ghis, Al Hoceima, Morocco

*Corresponding author El Ouai Driss

26


S.02: SEISMIC HAZARD AND NEW SEISMOGENIC ZONING IN THE STRAIT OF GIBRALTAR Abderrahman Elmahsani 1, Ait Brahim Lahcen 1, Tadili Benaissa 2, Tlemcani Mohammed 1, Abdelouafi Abdallah 1, Lallout Imane 1, Dahaoui Mohammed 1 1 - Faculté des sciences [Rabat] (Morocco), 2 - Université Mohammed V, Institut scientifique Rabat, Unité de recherche LGRN (Morocco)

Abstract The Rif chain is the result of the overlap of the thrust sheet over the northern part of Africa. This geodynamic context is governed by the collision of the African and Eurasian Cretaceous plates up to the present, this context is characterized by a complex tectonic activity, this gives rise to a seismic activity around the Mediterranean especially in the estern Mediterranean. This work aims to assess the seismic hazard in the Strait of Gibraltar by a probabilistic approach, based on a catalog of seismicity updated from several national and international agencies. We extracted the parameters of the Gutenberg-Richter law estimate, based on a new seismogenic zoning. The seismicity parameters thus determined, allowed us to realize the map of the maximum accelerations on the ground (PGA) for a return period of 50 years, by using the seismic hazard software CRISIS 2007. The maps thus obtained shows acceleration values that vary between 0.01g and 0.43g.

Keywords: Strait of Gibraltar, Seismic hazard, Gutenberg, Richter, PGA

*Corresponding author Abderrahman Elmahsani

27


S.02: THE 2016 MIHOUB (NORTH-CENTRAL ALGERIA) EARTHQUAKE SEQUENCE: SEISMOLOGICAL AND TECTONIC ASPECTS Khelif Mohamed Fadhlallah 1, Yelles-Chaouche Abdekrim 2, Benaissa Zahia 3 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria), 2 - Observatoire de Tamanrasset (Algeria), 3 Université des Sciences et de la Technologie Houari Boumediene [Alger] (Algeria)

Abstract On 28 May 2016 at 23:54 (UTC), an Mw5.4 earthquake struck Mihoub village, Algeria, 60 km southeast of Algiers. This earthquake was the largest event in a sequence recorded from 10 April to 15 July 2016. In addition to the permanent national network, a temporary network was installed in the epicentral region after this shock. Recorded event locations allow us to give a general overview of the sequence and reveal the existence of two main fault segments. The first segment, on which the first event in the sequence was located, is near-vertical and trends E?W. The second fault plane, on which the largest event of the sequence was located, dips to the southeast and strikes NE?SW. A total of 46 well-constrained focal mechanisms were calculated. The events located on the E?W-striking fault segment show mainly right-lateral strike-slip (strike N70°E, dip 77° to the SSE, rake 150°). The events located on the NE?SWstriking segment show mainly reverse faulting (strike N60°E, dip 70° to the SE, rake 130°). We calculated the static stress change caused by the first event (Md4.9) of the sequence; the result shows that the fault plane of the largest event in the sequence (Mw5.4) and most of the aftershocks occurred within an area of increased Coulomb stress. Moreover, using the focal mechanisms calculated in this work, we estimated the orientations of the main axes of the local stress tensor ellipsoid. The results confirm previous findings that the general stress field in this area shows orientations aligned NNW?SSE to NW?SE. The 2016 Mihoub earthquake sequence study thus improves our understanding of seismic hazard in north-central Algeria.

Keywords: earthquake sequence, algeria, coulomb stress, reverse fault

*Corresponding author Khelif Mohamed Fadhlallah

28


S.02: ASSESSMENT OF TEMPORAL VARIATION AND SPATIAL VARIATION OF RECURRENCE PARAMETERS IN THE GOLD MINING REGIONS OF SOUTH AFRICA Zulu Brian Sibonelo 1 2, Midzi Vunganai 1 2, Manzunzu Brassnavy 1 2, Durrheim Raymond 1 1 - Council for Geoscience (South Africa), 2 - School of Geosciences, University of Witwatersrand (South Africa)

Abstract The analysis of the seismicity recorded by the South African National Seismograph Network, Strategic Water Management Project and Mine Health and Safety Project in the northern rim of the Witwatersrand Basin of Gauteng Province, South Africa, shows that the recorded seismicity does not follow a Poisson distribution. The classical approach of seismic hazard analysis needs to be modified to account for temporal variation of recurrence parameters namely, a-value, b-value, Mc, and Mmax for all established seismic sources. The delineation of seismic source zones took into account both the spatial variation in completeness, as well as the spatial variance in the occurrence of seismicity. In order to assess these factors, the latitude and longitude of seismicity were plotted as a function of time. This resulted in establishment of four seismic sources, namely, Far West Rand (FWR), West Rand (WR), Central Rand (CR) and East Rand (ER). A change observed in the recorded seismicity for all zones is highly influenced by changes in monitoring capabilities as well as mining activity. Thus, in characterising the seismic zones, the time variation in seismicity was taken into consideration. Timedependent seismic source recurrence parameters were calculated for each seismic source using various software packages and techniques suitable to each seismic source parameter. The mining activities are continuing in the FWR and WR whilst they have discontinued in the CR and ER. Hence the abandoned mines in CR and ER are now flooding resulting in induced events and thus recent increase in seismicity.

Keywords: Spatial variation, Recurrence parameters, Seismicity, Temporal variation

*Corresponding author Zulu Brian Sibonelo

29


S.02: REASSESSING THE RUPTURE PROCESS OF THE 2003 BOUMERDES-ZEMMOURI EARTHQUAKE (MW 6.8, NORTHERN ALGERIA) USING TELESEISMIC, STRONG MOTION, INSAR, GPS, AND COASTAL UPLIFT DATA Beldjoudi Hamoud 1, Delouis Bertrand 2, Yelles Chaouche Abdelkrim 1, Kherroubi Abdelaziz 1 1 - Centre de recherche en astronomie astrophysique et géophysique (Algeria), 2 - Laboratoire Géoazur (France)

Abstract The Boumerdes-Zemmouri earthquake occurred ~50 km East of Algiers on May 21, 2003, at 19h44 (UTC). It is the second strong earthquake that struck northern Algeria, after the El Asnam earthquake (Ms=7.3) on 10 October 1980. The Boumerdes-Zemmouri event was the subject of many studies, among which several focused on the seismic source The 2003 rupture developed below the coastal area, partly under the sea. Deverchère et al. (2005) described active structures offshore which may have been activated during the 2003 earthquake. The motivation of this work is mainly twofold; i) combine for the first time a most comprehensive set of data, including teleseismic, strong motion, GPS, InSAR, and coastal uplift, in order to constrain in the best possible way the rupture model; ii) explore for the first time the possible coseismic activation of faults described offshore in Deverchère et al. (2005). Mahsas et al. (2008) proposed that post-seismic slip inferred from GPS measurements occurred between 0 and 5 km depth near the top of the coseismic rupture.Therefore, constraining the slip distribution is a real challenge and combining the different datasets having complementary coverage is the best approach that we can undertake. In this study, we explore kinematic rupture models of increasing complexity, taking into account previously published models and structural complexities proposed in the previous studies. In order to define an optimal model, we will assess to which point model complexity is justified by the data. Indeed, most of the available data in the near source area provide only a partial coverage of the rupture zone. Therefore, constraining the slip distribution is a real challenge and combining the different datasets having complementary coverage is the best approach that we can undertake. Nonetheless, we expect that it will be particularly difficult to constrain the rupture on the farthest offshore area.

Keywords:

rupture process, Boumerdes, Zemmouri, coastal uplift, geodetic data, seimological data

*Corresponding author Beldjoudi Hamoud

30


S.02: SPATIAL DISTRIBUTION OF ATTENUATION IN NORTHERN MOROCCO AND THEIR INTERPRETATION Boulanouar Abderrahim 1, Harnafi Mimoun 1, Dobrynina Anna 2, Rahmouni Abdelaali 3 1 - Earth Science Department, Scientific Institute, Rabat, Morocco (Morocco), 2 - Institute of the Earth's Crust (Russia), 3 - Faculty of Science, Mohammed V University (Morocco)

Abstract In the present study, we investigated the spatial distribution of attenuation based on the Coda wave of northern part Morocco. For this purpose, we analyzed sixty-six broadband events from local earthquakes which recorded by twenty-four stations deployed by the Scientific Institute of Rabat during 2008. Also, we selected five frequencies (0.75, 1.5,3,6 and 12Hz) and four lapse time windows (30s, 40, 50 and 60s). Then, the attenuation values are extracting by applying the back-scattering model proposed by Aki and Chouet (1975). Additionally, the spatial distribution maps of the attenuation of Coda wave for this region are generated. The maps describe the attenuation (inverse of quality factors) distribution in this area. We conclude that the region known several anomalies of Coda attenuation for all frequencies and all windows used, like Al Hoceim and Nador regions with high attenuation. This is due to due of the high seismic activity and the presence of many faults. They are also compared with the heat flow map for this study zone. Moreover, the attenuation of Coda wave decreases with increasing depth into the crust of this area. This last result is explained by the fact that the earth becomes homogeneous more one penetrates into the crust of this area. Finally, these results can be used not only for scientific research but also for practical field.

Keywords: Coda wave, Morocco, Al Hoceima, Seismic, Attenuation

*Corresponding author Boulanouar Abderrahim

31

Poster: Seismic source / Induced seismicity https://afsc2018.sciencesconf.org/192965/

S.02: THE 2018, 15 JANUARY EARTHQUAKE, ARRAIOLOS (PORTUGAL, M=4.9): RESULTS FROM THE BROADBAND SEISMIC NETWORK DATA AND MACOSEISMIC SURVEY. Caldeira Bento 1, Araújo A. Alexandre 2, Borges José 1, Fontiela Joao 3, Oliveira Rui 4, Wachilala Piedade 5 6, Bezzeghoud Mourad 7 8 1 - Institute of Earth Sciences and Physics Department- University of Evora and Department of Physics, ECT - University of Evora (Portugal), 2 - Institute of Earth Sciences - University of Evora and Department of Physics, ECT - University of Evora (Portugal), 3 - Institute of Earth Sciences - University of Evora (Portugal), 4 - University of Évora, Institute of Earth Sciences, Portugal (Portugal), 5 - Institute Superior of Education Science of the Huíla, Department of Nature Sciences, Huíla, Angola (Angola), 6 University of Évora, Institute of Earth Sciences, IIFA, Portugal (Portugal), 7 - Universidad de Evora (Portugal), 8 - Institute of Earth Sciences and Science ant Thecnology School- University of Evora and Department of Physics, ECT - University of Evora (Portugal)

Abstract On January 15, 2018, an M=4.9 earthquake, with epicenter north of Arraiolos, occurred. Although did not produced material or human damages, it was felt in great part of the Portuguese Continental territory, having aroused a great curiosity in the population. In the vicinity of the epicenter it reached intensity VI (Aldeia da Serra and S. Gregório), having been felt with intensity IV / V in the city of Évora, about 20km from the epicenter. In Lisbon, more than 100km away the epicenter, it was felt intensity III. The area where this earthquake occurred, although never it has produced an instrumental earthquake of this magnitude, was being observed by the scientific community for presenting an anomalous seismic activity in the regional context. The seismicity pattern in this area is usually organized by sequences, that seems to show two dynamics: 1) earthquake swarms without any relationship with any major event; 2) a main event followed by aftershocks. In any case, it is a superficial seismicity (H 1350 earthquakes above magnitude 3 per year), shallow (15km to 100 km depth) and moderate (Mw5 earthquakes and locations of 5>M>4.0 events for Northern Algeria and Morocco. It can be observed a relatively good agreement between locations for these two data sets, that is, minor earthquake locations could be used to forecast future places where will happen moderate to strong earthquakes. Then, a time-independent forecasting model based on the spatially smoothed seismicity rate of M>4.0 earthquakes is proposed. Initially, the area under study was divided into square cells. The number of earthquakes with magnitude M>4.0 that have taken place at a given cell is counted and spatially smoothed. The time-independent forecasting model is proposed from the computation of M>5.0 earthquake probabilities for each cell for different exposure times. Probabilities are computed assuming a Poisson process and the Gutenberg-Richter magnitude-frequency relationship. Among the obtained results, we highlight the delineation of potential areas, from a probabilistic point of view, to host future earthquakes with magnitudes and in the studied region.

Keywords: Forecasting, spatially smoothed seismicity, Algeria, Morocco.

*Corresponding author Mohamed Hamdache

87

Oral: Earthquake Hazard Assessment https://afsc2018.sciencesconf.org/190772/

S.07: SEISMIC HAZARD ASSESSMENT OF THE DEMOCRATIC REPUBLIC OF CONGO AND SURROUNDING AREAS BASED ON RECENT COMPILED SEISMIC ZONATION SOURCE MODELS Mavonga Tuluka Georges 1, Delvaux Damien 2, Durrheim Raymond 3, Lukindula Jeanpy 1 1 - Goma Volcanic Observatory (Congo - Kinshasa), 2 - Royal Museum of Central Africa, l (Belgium), 3 - School of Geosciences, Univ. of the Witwatersrand (South Africa)

Abstract A new probabilistic seismic hazard assessment has been performed for the Democratic Republic of Congo (DRC) and surrounding areas. The DRC encompasses both intra-plate and active tectonic areas associated with the Congo Craton and the western branch of the East African rift system, respectively. The seismic hazard assessment is based on a new Sub-SaharanGlobal Earthquake Model (SSA-GEM) earthquake catalogue with homogeneous magnitude representation (Mw).The initial declustered catalogue has 782 events. Tthe final catalogue declustered used for the seismic hazard assessment spans 55 years, from 1960 to 2015 with 398 events and a magnitude of completeness of about 4.5. The seismotectonic zonation was done on the basis of the regional geological structure, neotectonic fault systems, basin architecture and distribution of thermal springs and earthquake epicenters. Also, consideration was given to a regional strain rate model developed for the East Africa Rift by Stamps et al. in the frame of the GEM Strain Rate Project. The current area source model consists of a total of 15 seismic zones distributed over 6 main tectonic groups which we assume to have comparable rheological and mechanical behavior with respect to the underlying crustal geology. The Gutenberg-Richter seismic hazard parameters were determined by the least square linear me-thod.Hazard computations have been performed using the latest OpenQuake-engine (Version 2.7.0). Spectral acceleration has been computed at PGA and for the response spectral periods of 0.05 s, 0.1 s, 0.2 s, 0.5 s, 1 s and 2 s using four GMPE: two for active shallow crust and two for stable continental conditions for site soils corresponding to Vs30 =600, 760 and 1500 m/s . Result obtained in term of PGA is consistent with that obtained by Damien et al., using average value of PGA computed from three regional GMPE in 4 cities in Kivu Rift segment using Crisis 2012 software.

Keywords:

probabilistic seismic hazard assessment, seismic zonation source model, earthquake catalogue, openquake engine.

*Corresponding author Mavonga Tuluka Georges

88


S.07: THE AL HOCEIMA EARTHQUAKE SEQUENCE OF 1994, 2004 AND 2016: STRESS TRANSFER AND POROELASTICITY IN THE RIF AND ALBORAN SEA REGION Kariche Jugurtha 1 2, Meghraoui Mustapha 3, Timoulali Youssef 4, Cetin Esra 5, Toussaint Renaud 6 1 - Institut de Physique du Globe, CNRS-UMR7516, EOST - Universite de Strasbourg (France), 2 - USTHB, Laboratoire de Geophysique, FSTGAT, B.P. 32 El Alia, 16111 Bab Ezzouar, Algiers, Algeria (Algeria), 3 - Institut de Physique du Globe, CNRSUMR7516, EOST - Universite de Strasbourg (France), 4 - Department of Earth Science, Scientific Institute, University Mohammed V, 10106 Rabat, Morocco (Morocco), 5 - Department of Geological Engineering, Mugla Sitki Kocman University, 48000, Turkey (Turkey), 6 - Institut de Physique du Globe, CNRS-UMR7516, EOST - Universite de Strasbourg, F- 67084, France (France)

Abstract The 2016 January 25 earthquake (Mw 6.3) follows in sequence from the1994 May 26 earthquake (Mw 6.0) and the 2004 February 24 earthquake (Mw 6.4) in the Rif Mountains and Alboran Sea. The earlier two seismic events which were destructive took place on inland conjugate faults, and the third event occurred on an offshore fault. These earthquake sequences occurred within a period of 22 yr at ?25 km distance and 11?16-km depth. The three events have similar strike-slip focal mechanism solutions with NNE-SSW trending leftlateral faulting for the 1994 and 2016 events and NW-SE trending right-lateral faulting for the 2004 event. This shallow seismic sequence offers the possibility (i) to model the change in Coulomb Failure Function (CFF with low ? including the pore pressure change) and understand fault-rupture interaction, and (ii) to analyse the effect of pore fluid on the rupture mechanism, and infer the clock-time advance. The tectonic loading of 19?24 nanostrain yr-1 obtained from the seismicity catalogue of Morocco is comparable to the 5.0 × 1017 N·m yr-1 seismic strain release in the Rif Mountains. The seismic sequence is apparently controlled by the poroelastic properties of the seismogenic layer that depend on the undrained and drained fluid conditions. The stress-rate ranges between 461 and 582 Pa yr-1 with a CFF of 0.2?1.1 bar. The computed clock-time advance reaches 239 ± 22 yr in agreement with the ?10 yr delay between main shocks. The calculated static stress change of 0.9?1.3 bar, under pore-fluid stimulus added with well-constrained geodetic and seismic strain rates are critical for any seismic hazard assessment.

Keywords: Seismicity and tectonics, Dynamics: seismotectonics, Fractures, faults, and high strain deformation zones, Neotectonics

*Corresponding author Kariche Jugurtha ,

89


S.07: SEISMICITY RATE INFERRED FROM GEOLOGY MODEL AND IMPLICATION IN PROBABILISTIC SEISMIC HAZARD ASSESSMENT, THE CASE OF GAFSA FAULT IN SOUTHWESTERN TUNISIA Athmouni Malak 1, Ksentini Ahmed 2, Abbes Chedly 3 1 - PhD Student (Tunisia), 2 - assistant professor (Tunisia), 3 - Professor (Tunisia)

Abstract This work aims to estimate the seismic occurrence rates for the case of Gafsa fault in south western Tunisia. The evaluation is based on the geological parameters of the active fault. Using the local earthquake catalog, the rates were estimated for different magnitude binsby deploying the appropriate techniques. Then, the geological data were drawn from the bibliography in order to plot the yearly recurrence curves by means of global empirical prediction models. A comparison between the seismicity rates inferred from the earthquake catalog and the predicted rates inferred from the slip rates is presented and some correlation are found. A sensitivity analysis is conducted to evaluate the impact of uncertainties in events location on the final estimates.

Keywords: seismic occurrence rate, Gafsa fault, active faults, earthquake catalog, slip rates

*Corresponding author Athmouni Malak

90


S.07: TOWARD A HOMOGENEOUS MOMENTMAGNITUDE DETERMINATION FOR EARTHQUAKES IN SOUTH AFRICA: ANALYSIS OF UNCERTAINTIES IN MAGNITUDE CONVERSION Manzunzu Brassnavy 1 2, Brandt Martin 2, Midzi Vunganai 2, Durrheim Raymond 1, Saunders Ian 2

1 - University of the Witwatersrand [Johannesburg] (South Africa), 2 - Council for Geoscience (South Africa)

Abstract Earthquake magnitude is the most important parameter in the catalogue for seismic hazard analysis. It is known that the only consistent measure of magnitude is based on the seismic moment. However, most catalogues especially historical ones do not report moment magnitude, but have other magnitude types like local magnitude Ml, body wave Mb and surface wave magnitude Ms. In this regards, we present a first attempt to derive an earthquake moment magnitude (Mw) ? Local magnitude (ML) relation for South Africa with a general orthogonal regression. This may be approximated by Mw ~ ML - 0.15 ± 0.15 for the magnitude range 3.6 ?ML? 4.8. We carried out spectral analysis on the vertical component seismograms assuming a Brune model for the S-wave source radiation from which Mw can be computed. Locally derived attenuation functions for both mining related and purely tectonic events were used in the calculations. We verified our relation by comparison with those reported by the National Earthquake Information Centre (NEIC) and CMT. The new formulae were used to homogenise the new Catalogue for Johannesburg to moment magnitude for the period between 1964 and 2016. This relation will be used in future in the practice of magnitude determination for South Africa.

Keywords: Catalogue, South Africa, local magnitude, Moment Magnitude, Uncertainties

*Corresponding author Manzunzu Brassnavy

91

Poster: Earthquake Hazard Assessment https://afsc2018.sciencesconf.org/192229/

S.07: AN OVERVIEW OF: THE PROBABILISTIC SEISMIC HAZARD ASSESSMENT FOR SUDAN AND THE KHARTOUM SEISMICITY El Tahir Nada 1, Midzi Vunganai 2 1 - University of Khartoum (Sudan), 2 - Council for Geoscience (South Africa)

Abstract The seismic database used in this study consists of a regional catalogue. The catalogue was checked for completeness with respect to time and it was homogenised to a surface wave magnitude (Ms). Areal seismic zones were selected based on present day seismotectonic knowledge. The hazard calculations are done for rock sites. Since there are no ground motion prediction models for Sudan, we selected the SEA96 model, which was derived for extensional tectonic regimes similar to Sudan. In the results, regional hazard maps for 10% probability of exceedance in 50 years and 100 years were prepared. A maximum ground motion value of 0.2g was observed near the city of Juba for the hazard map of 10% probability of exceedance in 50years (i.e. return period of about 475years), and about 0.04g for Khartoum city from the hazard map of 10% probabilistic exceed dance in 50 years. Recently, the local seismic network around Khartoum, has recorded a few events. It is of particular interest to investigate the local seismicity around Khartoum in order to better establish the potential for large events, since a magnitude 5.5 event in Khartoum could be a disaster. Apparently, the area has a very low seismicity level with only a few local events per year, and there has not been any known events larger than Ml=4 since 1993. The long term seismicity rate is similar to the New Madrid area. The investigated seismic record and the calculations made in this work confirmed the presence of large geological structures which could support a large earthquake. Some of these structures are apparently seismically active. However, there is no evidence of historical large events. At the same time these small recent events are of great importance because they occurred close to the capital city, Khartoum.

Keywords: Hazard, sesimicity, Sudan.

*Corresponding author El Tahir Nada

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S.07: EVALUATION DE L'ALÉA SISMIQUE DE LA RÉGION DE CONSTANTINE (NORD-EST ALGÉRIEN) Hamidatou Mouloud 1, Mohammdi Yahia 1, Nassim Hellal 1 1 - CRAAG (Algeria)

Abstract Le nord de l'Algérie a subi plusieurs séismes majeurs et destructifs dans son histoire en raison de sa position sismotectonique à la frontière des plaques lithosphériques africaine et eurasienne. Le nord-est du pays a particulièrement souffert des effets du séisme du 27 octobre 1985 (I0=VIII) qui a détruit une partie de la ville de Constantine et qui a causé la perte de plusieurs vies humaines. L'objectif de cet article est d'analyser l'activité sismique de la région du Constantinois entre 1357 et 2014. Notre recherche est une contribution à l'amélioration de la gestion du risque sismique en évaluant l'aléa sismique dans la région du Constantinois. Des études visant l'évaluation de l'aléa sismique de cette région ont été réalisées dans le passé. Dans ce travail, on se propose de présenter les derniers résultats d'une étude probabiliste d'analyser de l'aléa sismique où les données nouvelles de sismotectonique et de sismicité sont incorporées. Pour réaliser et visualiser la modélisation de l'input sismique dans les zones urbaines, l'évaluation de l'aléa sismique et l'etablissement d'un catalogue de sismicité nord-est algérien, des graphes et des cartes ont été conçus à l'aide d'un système d'information géographique (SIG), le code ZMAP v. 6 et le logiciel CRISIS v. 2007.

Keywords: Aléa sismique, Zone source, Catalogue de sismicité, Accélération, Constantine, SIG.

*Corresponding author Hamidatou Mouloud

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S.07: SISMICITE ET RISQUE SISMIQUE AU MAROC Haou Youssef 1, Serroukh Mostafa 1, Ouazani Touhami Abdelouahed 1, Khald Hassan 2, El Mrihi Abdelaziz 1 1 - Département des Sciences de la terre Faculté des Sciences Tétouan, Maroc (Morocco), 2 - : Département de physique Faculté des Sciences Rabat, Maroc (Morocco)

Abstract Le Maroc a été affecté durant son histoire par des séismes, les premiers séismes recensés ne sont connus que depuis le IXéme siècle. L'objet de ce travail est d'étudier l'impact des séismes sur l'Hommes sur ses biens et d'évaluer l'apport des données de la sismicité historique à la connaissance globale de celle du Maroc. Nous avons élaboré un catalogue sismique. Celui-ci nous a permis de réalisé des cartes de sismicité dont l'analyse révèle une concentration de foyers dans la partie nord du Maroc avec une direction dominante NE-SW et nous a permis aussi la mise en évidence d'une activité sismique. Cette sismicité est représentée par un coefficient b de l'ordre de 1.158 valeurs qui indique que les séismes de faible à moyenne magnitude sont relativement plus fréquents que les séismes de forte magnitude. Nous avons déterminé dix zones sources couvrant l'ensemble du territoire. La délimitation de ces zones sources s'est basée sur les données géologiques, tectoniques, géodésiques, géophysiques et géotechniques, et d'autre part de la sismicité historique et instrumentale et des mécanismes au foyer. Pour chaque zone source nous avons calculé les valeurs de a et b de la relation de Gutenberg-Richter, le taux annuel de l'activité sismique l, la répartition spatiale des séismes, la magnitude maximale Mmax et la profondeur maximale des foyers. En nous basant sur un modèle adéquat, nous avons calculé l'accélération du sol pour cette région avec une probabilité de 90% de ne pas être dépassé durant des périodes d'observation de 50, 100 et 250 ans. Les résultats du traitement des données sismiques sont représentés sous forme de courbes d'iso-valeurs des accélérations en % de g. Nous avons obtenus des cartes des accélérations permettant de limiter les zones à risque dans cette région.La valeur maximalede 16% de g a été observée dans la région d'Al Hoceima.

Keywords: Sismicité/ Zone Source/ Risque Sismique/ Catalogue Sismique/ Maroc/

*Corresponding author Haou Youssef

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S.07: IDENTIFICATION DES PARAMÈTRES SISMIQUES RELATIFS AU SOL DE LA RÉGION DU GRAND NADOR Azougay Abdellah 1, Chaaraoui Aboubakr 1, Rezqi Halima 1, Chourak Mimoun 2, Oujidi Mostafa 1

1 - Applied Geosciences Laboratory (Morocco), 2 - Ecole nationale des sciences appliquées Oujda (Morocco)

Abstract L'estimation de l'aléa sismique dépend des données géologiques, géotechniques (la détermination de certains paramètres physiques), données de sismicité historiques et de l'effet de site, Elle contribue considérablement à l'évaluation du risque sismique. Afin de déterminer quelques paramètres tel que la période fondamental du sol et l'accélération maximale prévisible, Des mesures relative au bruit de fond ont été réalisées afin de déterminer la période prédominante relatives aux différentes formations géologiques par l'application de la méthode H/V (Nakamura, 1989). Ensuite, nous avons fait une carte de modélisation montrant l'attribution des fréquences propres des différents points de mesures aux couches géotechniques de surface (30m de profondeur), L'intérêt de la détermination des conditions locales du sol est très important pour éviter le phénomène de résonance (amplification dynamique du sol) sur les sites constructible. Les résultats montrent que les fréquences de faibles valeurs caractérisent les formations géologiques récentes (Quaternaire), tandis que les fréquences élevées correspondent à la formation basaltique du Gourougou. Les résultats constituent un outil important pour l'élaboration du Plan de Prévention du Risque Sismique de la région d'étude et un outil d'aide de décisions au profit des institutions en vigueurs.

Keywords: sol, paramètres sismiques, méthode H/V

*Corresponding author Azougay Abdellah

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S.07: SITE EFFECTS, AMPLIFICATION AND CHARACTERIZATION OF ALGIERS SEISMIC ZONE

SOIL

Chabane Souhila 1 2 3 4 1 - Djamel Machane (Algeria), 2 - Fatma Khaldaoui (Algeria), 3 - El-Hadi Oubaiche (Algeria), 4 - Rabah Bensalem (Algeria)

Abstract The Dar El Beida area, situated in the Mitidja basin, is characterized by its PlioQuaternary sediments, bordered by 2 faults. Indeed, the analysis thanks to the spectral ratio H/V ambient vibration method confirms these assumptions. An electric resistivity tomography strengthened the results obtained from ambient vibration for site characterization. The results obtained from various H/V curves shows that the values of frequencies vary from 3.9 to 5.5 Hz with varying standards deviations of ± 0.2 to ± 0.6 Hz. From the analysis of the derived H / V curves. The slope obtained by the SSE from the H / V analyzes is 8.13%, it is a dip of 4.65, The other slope towards the NNE is 4.5% with a dip of 2.6 °. This enables us to raise an interface plunging slightly towards the N and the S, which could suggest the presence of a convexity. The strongest amplitudes of the H/V curves (>5) are observed in the NW part of the site, the weakest towards the SE. This means that the velocity contrast is stronger in the NW part. This latter signified also that the most unstable grounds or those amplifying from the seismic point of view are partly in the NW of the study area; on the contrary, less amplifying grounds are located in the SE. Thanks to the results of the electrical imaging profile, we could model our terrain and determine two different layers with a contrast in terms of resistivity. The upper layer has stretched sub-layers and the deep layer shows tight layers in terms of "equidistance". The bumps of this interface mean that the frequencies may vary slightly. Indeed, the frequency of 11.8 Hz reflects the surface layer determined at 4 m and which is visible on the electrical imaging profile.

Keywords:

Site Effects, Amplification, Mitidja basin, H/V ambient vibration, electrical

imaging profile

*Corresponding author Chabane Souhila

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S.07: PRELIMINARY STUDY OF SEISMIC HAZARD ALONG THE CAMEROON VOLCANIC LINE Nana Gaelle Vanessa 1, Tokam Alain-Pierre 2 1 - University of Yaounde I (Cameroon), 2 - University of yaounde I (Cameroon)

Abstract Earthquakes frequently occur along the Cameroon Volcanic Line (CVL), with magnitude raging between 2 and 6. These events are from tectonics and volcanic origins. An experiment called Cameroon Broadband Seismic Experiment (CBSE) was conducted in the country between 2005 and 2007. These data collected was used in this work to computed the seismic hazard and therefore highlight the most risky areas around the CVL. We focused our analysis on one year period going from January to December 2005. On these data, we applied a pass band filter with frequency ranging from 1 to 5 Hz, then we did the picking of the P and S first arrivals. This allows to locate earthquakes. The located events were distributed along the Congo Craton margin. This gives are update view of the Cameroon neoseismicity. From the seismicity map and seismic hazard computation, we distinguished four risky areas: The mount Cameroon area, considered like the most seismically active; Then the southern Cameroon area it's seismicity is associated to the KribiCampo fault and also the presence of Congo Craton known for its high magnitude tectonic activity; The area along the Sanaga fault is the third risk zone; and the last one is the western Cameroon characterized by a large fault network.

Keywords: seismic hazard, seismicity, first arrivals

*Corresponding author Nana Gaelle Vanessa

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S.07: STRESS CHANGE AND FAULT INTERACTION FROM A TWO CENTURY-LONG EARTHQUAKE SEQUENCE IN THE CENTRAL TELL ATLAS, ALGERIA Kariche Jugurtha 1 2, Meghraoui Mustapha 1, Ayadi Abdelhakim 3, Boughacha Mohamed Salah 2 1 - Institut de Physique du Globe, CNRS-UMR7516, EOST - Universite de Strasbourg, F- 67084, France (France), 2 - USTHB, Laboratoire de Geophysique, FSTGAT, B.P. 32 El Alia, 16111 Bab Ezzouar, Algiers, Algeria (Algeria), 3 - Department of Seismology Centre de Recherche en Astronomy Astrophysique et Géophysique (CRAAG) Route de l'Observatoire, Bouzareah 16000 Algiers, Algeria (Algeria)

Abstract A sequence of major seismic events reaching Ms 7.3, with thrust faulting mechanisms, occurred from 1891 to 2003 in the central Tell Atlas of Algeria located along the Africa?Eurasia plate boundary. Previous neotectonic investigations show that earthquake faults of the central Tell Atlas have the potential to generate large magnitude earthquakes. We calculate the level of stress change that promotes the occurrence of a seismic sequence, taking into account the earthquake fault parameters, their uncertainties, the eastward earthquake migration, the seismicity rate change, and the interseismic strain accumulation. The computed coulomb failure function (?CFF) includes the seismicity rate and the stress transfer with fault interaction. The ?CFF modeling shows 0.1?0.8 bar increase on fault planes at 7 km depth with a friction coefficient ?? 0:4 with stress loading lobes on targeted coseismic fault zone and location of stress shadow across other thrust-and-fold structures of the central Tell Atlas. The coulomb modeling suggests a distinction in earthquake triggering between moderate-sized zones and large earthquake rupture zones. Following the 2003 earthquake, Global Positioning System, Interferometric Synthetic Aperture Radar, leveling studies, and aftershocks show that postseismic cumulative moment release amounts to 17.08%, which suggests an additional static stress change. In addition, the presence of fluid and related poroelastic deformation is considered as another parameter that favors stress increase and fault interaction. Modeling the stress change and fault interaction near major cities may contribute to a better constraint of the seismic-hazard assessment and risk mitigation in northern Algeria.

Keywords: Tell Atlas, Seismicity and tectonics, Fractures, faults, pore fluid flow

*Corresponding author Kariche Jugurtha

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S.07: RAPID EARTHQUAKE DAMAGE ASSESSMENT OF BUILDINGS USING FUZZY LOGIC APPROACH: APPLICATION TO ALGERIAN BUILDINGS Allali Sid Ahmed 1 2, Abed Mohamed 2, Mebarki Ahmed 1 1 - Laboratoire de Modélisation et Simulation Multi Echelle (France), 2 - Saâd Dahlab University [Blida] (Algeria)

Abstract Major earthquakes represent important issues to authorities, earthquake damage assessment tasks must be carried out after such disasters quickly and accurately in order to evaluate and classify buildings. Usually, visual inspections of damaged buildings are performed by qualified inspectors, however, making decisions about buildings safety under such urgent conditions of the aftermath of destructive earthquakes is absolutely a complex and crucial process, inspectors report always difficulties to evaluate and derive suitable global damage levels for affected buildings. Hence, this paper presents a theoretical approach to support the decision-making process of inspectors during damage assessment tasks by processing the observed damages in buildings' components to derive global damage levels. The proposed approach is based on fuzzy set theory and weighted fuzzy rules, buildings' structural and non-structural components are considered as inputs (parameters) to derive global damage levels, weighed fuzzy rules are proposed and their weights values are calibrated according to the influence of each component under each damage level on the building's global damage level. A database of a prior earthquake in Algeria of more than 30K evaluation forms is used to calibrate and validate the proposed approach, the performance of the approach is analyzed by assuming three scenarios to derive global damage levels: 1) considering only the non-structural components as influencing parameters, 2) considering only the structural components as influencing parameters, 3) considering all building's components as influencing parameters. Results show that the approach was able to predict correctly about 69% of cases in the first scenario, 85% in the second scenario and almost 90% in the third scenario.

Keywords: fuzzy logic, building, damage assessment, earthquake, weighted fuzzy rules.

*Corresponding author Allali Sid Ahmed

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S.07: EVALUATION DES DOMMAGES STRUCTURAUX POST-SÉISMIQUES PAR LES RÉSEAUX DE NEURONES Noura Hichem 1, Abed Mohamed 2, Mebarki Ahmed 3 1 - University Djilali Bounaama Khemis Miliana (Algeria), 2 - University Blida 1 (Algeria), 3 - University Paris-Est Marne-la Vallée (France)

Abstract Le présent article consiste à étudier l'efficacité des Réseaux Neurones Artificiels (RNAs) pour une évaluation rapide des dommages structurels après un tremblement de terre. Deux groupes de paramètres sont pris en considération : le groupe de composants structurels (infrastructure, élément vertical, contreventement, toiture et dalles), le groupe de composants secondaires (éléments non structuraux : escaliers, remplissages extérieurs, composants tels que balcons, cheminées etc). L'analyse des paramètres du réseau neuronal (RNAs) adéquate, c'est-à-dire le nombre de couches cachées et les neurones ainsi que les fonctions d'activation, donne la meilleure combinaison des dommages des composants qui gouverne le dommage global d'un bâtiment. Un ensemble de bâtiments endommagés est extrait d'une base de données récoltée au cours d'un sondage post-séisme par des techniciens qualifiés (séisme de Boumerdes, Algérie : Mw = 6,8 ; tremblement de terre du 21 mai 2003). La comparaison entre les dommages prédits et observés montre que la meilleure architecture du réseau de neurones correspond à une couche cachée avec un nombre de neurones égal au nombre de composants de construction (c.-à-d. 4 ou 8 composants). Les prévisions du RNAs et les dommages globaux observés sont conformes à : 70% lorsque le dommage global des bâtiments est supposé être influencé uniquement par le groupe d'éléments secondaires (non structurels), 80% pour les bâtiments lorsque les dommages globaux sont supposés être influencés uniquement par le groupe structurel, et 87% lorsque les dommages globaux des bâtiments sont supposés être influencés par les deux groupes de composants de construction, c'est-à-dire les composants structurels et secondaires.

Keywords: réseaux de neurones, bâtiments, dommages, Tremblements de terre, évaluation post

*Corresponding author Noura Hichem

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S.07: VULNERABILITY/DAMAGE CURVES FOR MAJOR CITIES IN SOUTH AFRICA Pule Tebogo 1, Fourie Christoffel 2, Kijko Andrzej 3, Midzi Vunganai 4 1 - Council for Geoscience (South Africa), 2 - Walter Sisulu university of technology (South Africa), 3 - University of Pretoria [South Africa] (South Africa), 4 - Council for Geoscience (South Africa)

Abstract Southern Africa is considered a stable continental region in spite of several cases of reported earthquakes, which caused considerable damage and casualties particularly in the mining industry. Most buildings and structures in South Africa are not designed to resist any intensity of earthquake. Most architects, engineers and builders in South Africa do not consider seismic resistance as a design requirement. This is mainly because the region has not experienced any serious destructive earthquake in recent years.The most destructive earthquake recorded in South Africa is the Ceres earthquake of 1969. The earthquake with a magnitude of 6.3 occurred on September 29, 1969 in the Ceres-Tulbagh region of the Western Cape Province about 100 km northeast of Cape Town. Serious damage occurred to certain buildings in the area (amounting to a total of U.S. $24 million). The structural damage varied from almost total destruction of old and poorly constructed buildings to large cracks in the better-built ones, twelve people were killed and many more were injured. Another event that caused severe damage to infrastructure occurred on 09th March 2005 at Stilfontein near Klerksdorp.Recent years have seen at least four mining induced tremors causing significant damage (Welkom 1976, Klerksdorp 1977, Welkom 1989 and Carletonville 1992). Such events show that it is, indeed, necessary to take seismic events into account in the design of any infrastructure. Assessing and understanding the risk facing South African cities as a result of major seismic activity have been paid little attention. The main focus of this study is to develop the most suitable damage curves for major cities in South Africa. Therefore, the main results are damage curves for twelve of the most common building classes in South Africa, to show the extent of damage expected to a certain building class, with a certain earthquake magnitude.

Keywords: vulnerability, building classes, earthquake, structural damage

*Corresponding author Pule Tebogo

101

Oral: Geodynamics, GPS, InSAR and remote sensing https://afsc2018.sciencesconf.org/193070/

S.08: MAPPING OF LANDSLIDES BY INTERFEROMETRY RADAR CASE OF LANDSLIDES IN TAOUNATE PROVINCE IN NORTHERN MOROCCO Said Benchelha 1, Hassnaa Chennaoui 1, Mustapha Hakdaoui 2, Omar El Kharki 3, Taoufik Benchelha 4 1 - GAIA Laboratory. Hassan II University. Aïn Chock Sciences Faculty (Morocco), 2 - LGAGE Laboratory Hassan II University. Ben M'sik Sciences Faculty (Morocco), 3 - Faculty of Sciences and Techniques (Morocco), 4 - BENYA DEVELOPMENT (Morocco)

Abstract Northern Morocco is characterized by relatively young mountains experiencing a very important dynamic compared to other areas of Morocco. The dynamics associated with the formation of the Rif chain (Alpine tectonics), is accompanied by instabilities essentially related to tectonic movements. The realization of important infrastructures (Roads, Highways,...) represents a triggering factor and favoring landslides. Several methods can be used for landslide mapping, including Landsat 8 and Sentinel1 radar imagery. In this paper, the SAR Differential Interferometry (DinSAR) technique was applied to a couple of SLC-sentinel-1 images to highlight terrain movements at a site in Taounate Province. Despite the unfavorable conditions for InSAR due to vegetation cover, radar remote sensing observations provide valuable information that can be used for the assessment of landslide risk at the study area level. An adaptive phase filtering process has been used to improve the coefficient of coherence. The results obtained have been validated by GPS mapping.

Keywords: DinSAR, Landslides, Interferometry, Sentinel1, Cartography, GPS, InSAR.

*Corresponding author Said Benchelha

102


S.08: POTENTIAL FIELDS INTERPRETATION IN THE NW OF ALGERIA: EVIDENCES OF ACTIVE FAULTS AND UNDERGROUND STRUCTURE. Boukerbout Hassina 1, Abtout Abdeslam 1, Yelles-Chaouche Abdelkarim 1, Bouyahiaoui Boualem 1

1 - Centre de Recherche en Astronomie, Astrophysique & Géophysique-Observatoire d'Alger. (Algeria)

Abstract The NW of Algeria is known as one of the most seismic active zone in Algeria and the West Mediterranean region. It constitutes a key area to study neotectonics structures and their geodynamical context. Until now, there is a little information about existence of deep active faults, which generate this strong activity. Potential fields data (aeromagnetic and gravity) are an important resource of information on crustal structure. The aim of this work is giving a reliable geometry of the major faults relative to the kinematics of this region. The results obtained from various filtered maps (shaded relief, derivatives, upward continuation) of the magnetic and gravity data were used to generate a structural map of the studied area. Whilst the continuous wavelet and ridgelet transforms can help in automatic detection of elongated structures in 3-D both onshore and offshore, to estimate their strike direction, shape and depth. The short wavelength potential fields anomalies are related to volcanic rocks on the coast and to the basement in sedimentary basins. The long wavelength anomalies are associated mainly with deep E-W structures, limiting the basins. In the North, similar structures have been identified in the Mediterranean Sea. This work yields to a 3-D image of the region and confirms the existence of several faults, localized or inferred, from former geological studies.

Keywords:

2D and 3D imaging, deep structures, faults and contacts, structural map, potential fields data, aeromagnetic and gravity anomalies, wavelet transform, ridgelet transform

*Corresponding author Bouyahiaoui Boualem

103


S.08: PLIO-QUATERNARY TECTONIC INVERSION EVIDENCED ALONG THE ALGERIAN MARGIN Yelles Abdelkarim 1, Aidi Chafik 1, Beslier Marie-Odile 2, Lamine Hamai 3 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria), 2 - Geoazur (France), 3 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria)

Abstract The Neogene evolution of the western Mediterranean region has resulted from the break off of the ALKAPECA domain and the southward drift of the Kabylian blocks. From the two marine surveys conducted along the Algerian margin: the SPIRAL (September 2009) and the MARADJA (2003/2005 s), it is evidenced that after the opening of the several basins of the western Mediterranean region, a Plio-Quaternary tectonic inversion process have affected the Algerian margin. We present here the Plio-Quaternary inversion using the seismic data set collected during two surveys. Tectonic inversion is at the deep margin displays a flat-ramp compressive system in the deep sedimentary series, which emerges at the foot of the continental slope and marks the seaward limit of a P-Q basins perched at mid-slope. The southdipping ramps are neo-formed structures, whereas the flats use inherited lithologic discontinuities (base of the Messinian evaporitic series, top of the acoustic basement). The inversion tectonic process explain the actual compressive stress regime of northern Algeria marked by the seismicity of this region.

Keywords: tectonic inversion, Algerian margin, seismic data

*Corresponding author Yelles Abdelkarim

104


S.08: AN INITIATION OF A SUBDUCTION ZONE ALONG THE ALGERIAN MARGIN: WHAT DOES THERMOMECHANICAL MODELING SAY? Hamai Lamine 1, Yelles-Chaouche Abdelkarim 1, Petit Carole 2, Le Pourhiet Laetitia 3, Abtout Abdeslam 1, Déverchère Jacques 4 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria), 2 - Géoazur (France), 3 - Institut des Sciences de la Terre de Paris (France), 4 - UMR6538 Domaines Océaniques (France)

Abstract North Africa is undergoing a slow compression deformation due to the convergence current African-Eurasian. The deformation occurs on the continental margin (Frizon de Lamotte et al., 2011), as evidenced by the active seismicity recorded both on land and at sea (Yelles-Chaouche et al., 2006). This margin can thus represent a transitional step between the parameters of active and passive margin (e.g., Jolivet et al., 2006). The latest studies (SPIRAL, 2009) show signs of active or recent compressive deformation along this margin and Isostatic anomaly models show that the Algerian margin has isostatic anomalies close to that of an active margin (Hamai et al., 2015). In this work, we try to answer two questions: I) which rheological and thermal parameters control the location of compressive deformations at the old passive margin toe ? II) Are these parameters suitable for long-term evolution of the North Algerian margin to mature subduction zone? To test the effect of thermal and rheological parameters on the tectonic inversion of a passive margin, characterized by a young hot oceanic area, adjacent to a colder continental continent, we use thermomechanical modeling (pTatin, May et al., 2014). These two domains are separated by an ocean-continent transition zone (OCT) in a configuration similar to the northern Algerian margin. Finally, we test the effect of a smooth thermal gradient between the ocean and the continent and a clear vertical line between oceanic and continental geotherms. Our model results indicate that the tectonic inversion may progress to subduction when the OCT plunges into the continent or to an indentation of the lower continental crust by oceanic lithosphere when the transition zone is vertical. In both cases, the localization of deformations at the foot of the margin occurs only when it is sufficiently heated by the adjacent oceanic domain.

Keywords:

mechanical models, thermos, initiation of subduction, North African margin, thermal and rheological parameters.

*Corresponding author Hamai Lamine

105


S.08: ESTIMATION OF VERTICAL MOVEMENTS IN THE RIF MOUNTAINS (MOROCCO) USING PERMANENT GPS MEASUREMENTS, TIDE-ALTIMETRY AND SEISMICITY Fatima Ezzahrae Al Makkassi 1, Tahayt Abdelilah 2, Fadil Abdelali 3, Abdellah Elkenz 1, Reilinger Robert 4 5, Angel Ciberia 6, Mourabit Taoufik 7, Harnafi Mimoun 8, Amar Mohamed 9 2 1 - Université Mohammed V-Agdal (Morocco), 2 - Université Mohammed V-Agdal (Morocco), 3 - GEOHYD Laboratory, Geology Department, Semlalia Sciences Faculty, Cadi Ayyad University (Morocco), 4 - Massachusetts Institute of Technology (United States), 5 - MIT Parsons Laboratory (United States), 6 - Real Instituto y Observatorio de la Armada (Spain), 7 - Faculty of Sciences and Techniques, Mohammed 1st University (Morocco), 8 - Seismic Waves and Earth Structure research unit, Scientific Institute, Rabat - Morocco (Morocco), 9 - Agence Nationale de la Conservation Foncière, du Cadastre et de la Cartographie (Morocco)

Abstract The present-day horizontal movements in Morocco have been the subject of several studies using two decades of GPS measurements. These studies suggested models on the geodynamic processes in the western Mediterranean region. However, vertical component of the movements, often of smaller magnitude, are still poorly constrained. In this work we use permanent GPS measurements from 2009 to 2015 to estimate both horizontal and vertical components of tectonic movements in the Rif's domain. . The obtained GPS velocity field shows a low vertical movement as a subsidence of 1~2 mm/yr as indicated by 5 GPS stations (TETN, TANG, CEU1. HOCM, MELI). Moreover, ISGN station shows a very striking uplift about 4 mm/yr. The preliminary results disagree with geological estimates. On one side, the region between Tangier and Sebta is supposed to be affected by a quaternary uplift, on the other hand, the external zone of the Rif (ISGN) shows a quaternary subsidence. Meanwhile we aim to find a combination between GPS data and tide-altimetry data and seismicity in the Rif.

Keywords: Vertical movements, GPS, Tide, Altimetry, Seismicity Rif, Morocco.

*Corresponding author Fatima Ezzahrae Al Makkassi

106


S.08: NEW CONSTRAINTS ON THE NUBIA-EURASIA PLATE BOUNDARY KINEMATICS FROM GPS MEASUREMENTS IN ALGERIA Bougrine Amina 1 2 3, Yelles Karim 1, Calais Eric 3, Bellik Amar 1, Mahsas Abdelhakim 1, Terki Toufik 1 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria), 2 - Université Abou-Bakr Belkaïd Tlemcen (Algeria), 3 - Laboratoire de géologie de l'ENS (France)

Abstract Northern Africa is the locus of significant seismicity as a result of the oblique convergence between the Nubian and Eurasian plates in the Western Mediterranean. However, the kinematics of plate boundary deformation in this region remains unresolved because of a lack of quantitative data in the Maghrebides, east of the Gibraltar strait and the Alboran domain. Here we present new results based on continuous GPS data from 54 sites of the Algerian REGAT network, which spans 1200 km along the Algerian coast and 300 km inland, with a mean inter-site distance of 100km. We processed the 2007-2017 REGAT data together with 34 IGS sites using the GAMIT/GLOBK software. The resulting velocity field shows the expected NW-SE convergence between Nubia and Eurasia increasing gradually from east to west. We computed 2D strain accumulation models along 3 profiles as well as a 3D kinematic model to estimate crustal block rotations and fault slip rates. The best-fit models show that a significant portion of the Nubia-Eurasia convergence is accommodated offshore along the Algerian margin on south dipping slip faults at shallow depths with a maximum amount offshore Algiers, consistent with results from recent offshore geophysical investigations. In the western half of Algeria, data and models show that strain is confined to the coastal area, possibly involving slip on Neogene basin faults. In the eastern half of Algeria, plate boundary deformation is more broadly distributed, with lower slip rates on the offshore fault system, significant slip on an E-W right-lateral strike-fault through the Tellian Atlas, and some shortening likely accommodated along the southern border of the Saharan Atlas. These results place new constraints on seismogenic faults in the western Mediterranean with direct implications for regional seismic hazard. Further research requires densifying the GPS measurements and possibly combining it with InSAR.

Keywords: Algeria, boundary kinematics, deformation, GPS

*Corresponding author Bougrine Amina

107


S.08: ACTIVE TRANSFORM FAULTS IN THE GULF OF GUINEA: INSIGHTS FROM GEOPHYSICAL DATA AND IMPLICATIONS FOR THE SEISMIC HAZARD ASSESSMENT Meghraoui Mustapha 1, Amponsah Paulina 2, Bernard Paul 3, Ateba Bekoa 4 1 - Institut de Physique du Globe, CNRS-UMR 7516 (France), 2 - National Data Centre, National Nuclear Research Institute, Ghana Atomic Energy Commission (Ghana), 3 - IPG Strasbourg, CNRS-UMR 7516 (France), 4 - Institute of Geological and Mining Research, Yaounde, & Mount Cameroon Volcano Observatory, Cameroon (Cameroon)

Abstract Although the seismotectonics of Western Africa show the occurrence of major earthquakes (e.g., 1636 southwestern Ghana, 1939 offshore Accra; 1945 Cameroon-Congo border; 1983 Gaoual-Guinea) and prominent offshore transform fault, there is no analysis of the region that links the continental active tectonics with the oceanic fault zones (FZ) of the Gulf of Guinea region. Our study shows first the mapping of main faults using the bathymetric, gravimetric and magnetic data. We also associate regional seismicity (historical and instrumental seismicity) with focal mechanisms according to the Seismotectonic Map of Africa *. In the oceanic domain, we identify four main seismogenic fault zones, the Charcot FZ, Romanche FZ, Saint Paul FZ and Arkhangelskiy FZ. All of these faults have experienced large (Mw ? 6) to major (Mw ? 7) earthquakes during the last 50 years. We also calculate strain rates on these faults from late Cretaceous (-85 Ma) to present times using paleomagnetic and seismic moment data. The strain rates show a first stable trend around 2cm/yr then accelerate to 4 cm/yr in the last 10 million years. The comparison of late Quaternary strain rates with geodetic strain rates shows an accumulation of seismic energy on the Saint Paul FZ. The accumulation of seismic energy could lead to the initiation of a 7 to 7.5 Mw earthquake along the fault. Our seismotectonic analysis suggests the links between oceanic and continental tectonics, with about 20° anticlockwise fault trend rotation especially on the Saint Paul FZ. The potential for the occurrence of large earthquakes in the Gulf of Guinea should be taken into account for a realistic regional seismic and tsunami hazard of the Gulf of Guinea.

Keywords: West Africa, transform faults, earthquakes, gravity, magnetic data

*Corresponding author Amponsah Paulina

108


S.08: THE REACTIVATION CLUES OF THE EAST-ALGERIAN MARGIN Bouyahiaoui Boualem 1, Sage Françoise 2, Abtout Abdeslam 1, Yelles-Chaouche Abdelkarim 1 1 - CRAAG (Algeria), 2 - Géoazur (France)

Abstract In this work, we analyze the crustal structure of the eastern Algerian basin and its southern margin in the Annaba region (easternmost Algeria), from a set of geophysical data collected during the SPIRAL cruise in 2009, which included a wide-angle, 240-km-long, onshore-offshore seismic profile, multichannel seismic reflection lines, and gravity and magnetic data, complemented by the available geophysical data for the study area. We discuss the localization of the recent deformation related to the margin reactivation compared to the main lithospheric domains of the margin-basin system, in order to better understand the terms of the structural inversion. The analysis of seismic reflection profiles with different resolutions shows that the recent crustal deformation related at the reactivation of the northern Algerian border is mainly located in continental domain, at the necking zone, where the topographic gradient of the top and the base of the crust are strongest. On the edge of the deep basin, only the sediments would be engaged in the deformation, where the crustal faults of the necking zone emerge. Thus, this part of the margin would be the more deformable of margin-basin system, and would be sufficiently deformable to not transmit the deformation to the deep basin as well as hyper-thinned continental domain as the oceanic domain.

Keywords: Algerian basin, seismic data, deformation, geodynamic evolution

*Corresponding author Bouyahiaoui Boualem

109


S.08: CURRENT STATE OF UNDERSTANDING OF TECTONICS IN MOROCCO FROM TWO DECADES OF GEODETIC OBSERVATIONS Tahayt Abdelilah 1 2, Reilinger Robert 3, Floyd Michael 3, King Robert 3, Mourabit Taoufik 4, Koulali Achraf 5, Fadil Abdelali 6, Vernant Philippe 7, Mazzotti Stephan 7, Harnafi Mimoun 2, Rimi Abdelkrim 2, Amar Mohamed 8, Davila José-Martin 9, Pazos Antonio 9 1 - Centre National pour la Recherche Scientifique et Technique, Rabat, Morocco (Morocco), 2 - Scientific Institute, Mohammed V University of Rabat, Morocco (Morocco), 3 - Massachusetts Institute of Technology (United States), 4 - Faculty of Sciences and Techniques, Mohammed 1st University (Morocco), 5 - Australian National University (Australia), 6 - Cadi Ayyad University (Morocco), 7 - Université Montpellier 2 (France), 8 - Agence Nationale de la Conservation Foncière, du Cadastre et de la Cartographie (Morocco), 9 - Real Instituto y Observatorio de la Armada (Spain)

Abstract Morocco is part of the complex convergence zone between the Africa and Eurasia plates. Convergence is associated with active shortening across the major mountain belts resulting in a high seismic risk. The 1960, Agadir M5.7 (12,000 deaths) and 2004, Al Hoceima M6.3 (629 deaths) earthquakes, while of moderate magnitude, are the most catastrophic contemporary seismic events in Morocco. Seismic hazard analysis requires understanding the mechanics of active deformation at the local and regional scale, with improved observations, integrating geodesy, geology and geophysics. We currently have a quite dense GPS network bringing together Moroccan, US, French and Spanish institutions. In total, there are about 20 permanent stations and 45 measurement points spread throughout Morocco. Fourteen other stations are presently being installed. Special attention has been focussed on understanding the mechanics of active deformation and the relationship to plate boundary processes in the Western Mediterranean. During two decades, many geodetic observations have been introduced to highlight the importance of active tectonics in Morocco: 1 GPS measurements since 1999 have defined the deformation pattern of tectonic blocks, including motion and deformation of the Rif ?block? and slow convergence across the High Atlas Mountains. A movement of 5.4 ± 1.5 mm/yr towards the SSW with respect to fixed Nubia was estimated in the central Rif block, and convergence across the Atlas of 1.6 ± 0.5 mm/yr. 2 Radar interferometry has been widely used in the study of the Rif deformation. This technique played a key role in the characterization of the co-seismic displacements of the 1994 and 2004 Al Hoceima earthquakes. In this presentation, we will update results from GPS observations throughout Morocco and across the Alboran Sea and southernmost Spain through 2017 to constrain better active deformation in the westernmost Nubia-Eurasia continental collision zone.

Keywords: Seismic hazard, active tectonics, Geodynamic, InSAR, GPS, Geodesy, Western Mediterranean, Morocco *Corresponding author Tahayt Abdelilah

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S.08: PRESENT-DAY VERTICAL DEFORMATION IN NEW ZELAND FROM TWO DECADES OF GPS DATA Fadil Abdelali 1, Tenzer Robert 2, Almakkassi Fatimaezzahrae 3 1 - GEOHYD Laboratory, Geology Department, Semlalia Sciences Faculty, Cadi Ayyad University (Morocco), 2 - The Hong Kong Polytechnic University, PolyU, Department of Land Surveying and Geo-Informatics (China), 3 - Faculty of Sciences, Mohammed V University of Rabat, Morocco (Morocco)

Abstract We investigate the relationship between present-day vertical crustal motion and tectonic block configuration. The study is conducted along the active tectonic margin between the Australian and Pacific tectonic plates in New Zealand with a well-defined tectonic block configuration. For this purpose, the rates of vertical crustal motions relative to the ITRF2008 reference frame are estimated based on processing the GPS data (provided by the GeoNET project) collected at 123 continuous GPS sites. The numerical results showed an uplift of the central Southern Alps at the current rate of 4.5 mm/yr. This tectonic uplift is coupled in the South Island by the subsidence on both sides of the Southern Alps. The detected rates of subsidence in the eastern South Island are typically less than 1 mm/yr. The subsidence in the Buller Region (in the northwest South Island) is 1.4?1.5 mm/yr. Except for the Taupo Volcanic Zone and the upper Raukumara Block (in the central and northeast North Island), the subsidence is prevailing in the North Island. The systematic subsidence up to 9 mm/yr is detected along the Dextral Fault Belt (in the lower North Island). The largest localized vertical displacements (between ?10 and 17 mm/yr) in the Taupo Volcanic Zone are attributed to active tectonics, volcanisms and geothermal processes in this region. A classification of these vertical tectonic motions with respect to the tectonic block configuration reveals that most of tectonic blocks are systematically uplifted, subsided or tilted, except for regions characterized by a complex pattern of vertical motions attributed to active geothermal and volcanic processes.

Keywords: GPS, tectonic setup, vertical crustal motion, volcanism

*Corresponding author Fadil Abdelali

111


S.08: FUSION SENTINEL-1 SAR WITH SENTINEL-2 OPTICAL TO EVALUATION AND MONITORING THE DYNAMICS OF TERRITORIES Mahyoub Sulaiman 1, Rhinane Hassan 2, El Mehdi Monsour 2, Fadil Abdelhamid 3 1 - Geosciences Laboratory, Faculty of sciences Ain Chock Hassan II Univesity (Morocco), 2 - Geosciences Laboratory, Faculty of sciences Ain Chock Hassan II University (Morocco), 3 - Hassania School of Public Works (Morocco)

Abstract The most important thing in remote sensing is to extract the valuable information through various satellite sensors that have different specifications. Image fusion allows the user to combine different spatial and spectral resolutions to improve the information for objectives such as evaluation and monitoring the dynamics of territories, newly the European Space Agency (ESA) lunched Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 Multispectral Imager (MSI) sensors which have very different spatial and temporal resolutions (Sentinel-2 MSI sensor 10 m, 20 m and 60 m, nearly 5 days with 2 sensors; Sentinel-1 SAR sensor Stripmap 5 m, nearly 5 days with 2 sensors too). In this paper we investigate the fusion of SAR and optical for classification and mapping of dynamics of territories. Alhodaydah in western part in Yemen and alrachdia in eastern part in morocco were selected as a case study. The SAR image was terrain-corrected, speckle-filtered and coregistered to the simulated Sentinel-2 image. After radiometric and spatial resampling, the fused image stack was segmented and classified by SVM as proposed. Different fusion strategies are tested including fusion at the feature level and at the decision level. The analysis reveals that the best result can be obtained when the fusion of change information is carried out at the feature level.

Keywords: Remote sensing, dynamics of territories, ESA, SAR, MSI, feature level and feature level

*Corresponding author Mahyoub Sulaiman

112


S.08: MULTISOURCE APPROACH FOR MONITORING SPATIAL POSITION AND MOISTURE/DRYNESS SURFACE INFORMATION OF WATER CAVITIES OF IMLILY SEBKHAT IN SOUTHWESTERN MOROCCO Hakdaoui Sofia 1 2, Emran Anas 2 1 - Earth Observation Lab (Morocco), 2 - Earth Observation Lab (Morocco)

Abstract Sebkhats zones represent a wet depressions in desert environments, they are generally considered as floodable wetlands of great environmental interest strongly linked to numerous environmental issues such as climate change, water quality, wildlife habitat and the biodiversity. The studies carried out recently by our team in the Sebkhat of Imlily in the south of Morocco, have shown that these geomorphological structures often contain the marks of the last climatic variations in the Sahara. The Sebkhat of Imlily represents a zone of intrigue to scientists, for cause more than 160 permanent water cavities, 0.4 and 4.6 m deep and the water has a salinity between 24 and 350g / liter, however it hosts life, many animals and fishes had been reported during a scientific field trip in January 2009. For this study, optical and radar images are used to contribute to understand the functioning of the Sebkhat through the discovery of underground hydrological networks. These data had contributed to the updating of the recent geological map made in 2012, by the Moroccan geological service. The main objective is to investigate and evaluate capability of the complementarity of multisensory optical data and SAR radar in this particular desert environment. Results have revealed that radar images are not only well suited to the study of desert areas, but also allow better monitoring of spatial position of water cavities in these flood zones. Their sensitivity to variations in slope of the topographic surface improves the geological and geomorphological analysis of these deserts zones.

Keywords: InSAR, Remote Sensing, Multisensor Optics, Sebkhat, Southern Morocco

*Corresponding author Hakdaoui Sofia

113


S.08: CONTRIBUTION OF THE THERMAL INFRARED BAND OF LANDSAT SENSORS (TM & ETM+) TO SPATIOTEMPORAL MONITORING OF SURFACE WATER TEMPERATURE ALONG THE AL MASSIRA LAKE BETWEEN 1987 AND 2017 Aitelghazi Abdellah 1, Rhinane Hassan 2, Bensalmia Ahmed 3 1 - AIT EL GHAZI (Morocco), 2 - RHINANE (Morocco), 3 - BENSALMIA (Morocco)

Abstract Water remains a substantial resource that is threatened in its quality and quantity. Despite building new dams, Morocco will record a water deficit by the year 2025. This is mainly due to different natural problems affecting the reservoirs created by these dams that retain water. In this study we demonstrated the contribution of thermal infrared remote sensing to spatiotemporal monitoring of surface water temperature along the reservoir created by AL MASSIRA dam between 1987 and 2017. During this study we were able to represent the results on thermal and turbidity maps at several dates, illustrating the spatial distribution of surface water temperature since 1987. The thermal discrimination is noticed more precisely at the mouth of the reservoir, where the surface water temperature was more weakly distributed in 1984 than in 2017 since it became predominant in the same area of the reservoir. The analysis of the thermal data of TM6 band allowed us to create temperature maps illustrating the spatial and temporal distribution of this physical quantity along the reservoir. Thus, the correlations made between temperature and turbidity due to the presence of mineral matter and phytoplankton showed a strong positive correlation whose coefficient was estimated at 0.80 (R2). The linear equations deduced from this correlation allowed us to estimate and quantify the spatial distribution of the lake clarity as well as the density of suspended particles in water based on thermal infrared remote sensing data.

Keywords: AL MASSIRA lake, remote sensing, GIS, Landsat (5, 7), Sensor (TM & ETM +), thermal infrared band 6.

*Corresponding author Aitelghazi Abdellah

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S.08: SEISMOTECTONICS OF THE 2017 BOTSWANA EARTHQUAKE (MW 6.5): AN ACTIVE BRANCH OF THE EAST AFRICAN RIFT Meghraoui Mustapha 1, Midzi Vunganai 2, Mohamed Saleh 1 3, Kwadiba Tarzan 4, Manzunzu Brassnavy 5 2, Mulabisana Thifhelimbilu 6, Pule Tebogo 6, Saunders Ian(6) 1 - Institut de physique du globe de Strasbourg (France), 2 - Council for Geoscience (South Africa), 3 - National Research Institute of Astronomy and Geophysics [Helwan] (Egypt), 4 - Botswana Geoscience Institute (Botswana), 5 - University of the Witwatersrand [Johannesburg] (South Africa), 6 - Council for Geoscience (South Africa)

Abstract The 3 April 2017 Botswana earthquake occurred along a moderately seismic active zone in central southern Africa, west of the 2006 Machaze earthquake (Mw 7.0). Although located in the continental interior of the African plate, the seismogenic area previously considered as a stable region reveals a background seismicity associated with long-term deformation and faulting. We study the mainshock area using the seismotectonic data of the recent published map of Africa * and the Archean Limpopo?Shashe Tectonic Belt (ALSTB), the geodetic (InSAR) analysis and aftershock data determined from a postearthquakelocal seismic array. The mainshock location (25.18E, 22.6S) and depth (25 +-3 km) provided by the Council for Geoscience (Pretoria), EMSC and USGS was followed by the largest aftershock with Mw 4.5 on the 5 April 2017. Our analysis of Sentinel-1 interferogram (ascending orbit) shows 4 to 6 cm coseismic slip on a NW-SE elongated and 30-km-long rupture consistent with the mainshock location, normal faulting mechanism and source time function (http://geoscope.ipgp.fr/index.php/en/catalog/). We also investigate the earthquake rupture dimension at depth from the inversion of surface deformation and obtain slip distribution on a fault plane striking 315°, dipping 45° and -80° rake and with Mo 7.12 e18 N.m. The rupture geometry is in agreement with the 500 aftershock locations and confirms the 28 km seismogenic thickness. The earthquake sequence affected the ALTSB that defines the central Limpopo belt. The ALTSB appears as an analog of the NESW trending Okavango active zone that experienced the Ml 6.7 earthquake in 1952. Although the seismic strainrate is of low level, the 2017 earthquake rupture characteristics and related seismotectonic framework classify the intraplate region as an active plate interior.

Keywords: Botswana, earthquake, InSAR, aftershocks, seismotectonics, continental interior

*Corresponding author Meghraoui Mustapha

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S.08: GEODYNAMIC FRAMEWORK OF THE NORTHERN AFRICAN MARGIN IN TUNISIA : IMPLICATION FOR SEISMOGENIC POTENTIAL Bouaziz Samir(1) 2 1 - Ecole Nationale d'ingénieurs de Sfax, Département de Génie Géologique (Tunisia), 2 - University of Sfax, National Engineering School of Sfax, LR. ?Water-Energy-Environment? (Tunisia)

Abstract The northern African margin in Tunisia is a privileged area for geodynamic reconstruction due to well identified morpho-tectonic domains (i.e., Tellian, Atlas belt, N-S axis, Eastern platform and Saharan platform). These domains resulted from a complex tectonic evolution that started with the beginning of Pangea break-up, and ended during the Cenozoic Alpine orogeny of the Maghrebide chain. The sedimentary cover was folded and faulted during main paroxysm episodes. Within the Africa-Europe convergence zone, Tunisia is marked by dominant tectonic features, including thrusting, strike-slip faults and folding ; it has major rupture zones that affect Quaternary deposit. In fact, most of Tunisian land is seismically active with significant historical and active deformations, showing recent seismic events. Tunisia is currently prone to a continuous seismotectonic activity actually represented by moderate seismicity magnitudes. The investigation has provided crucial information on the tectono stratigraphy history and seismotectonics in each domain which affect remote orogenic dynamics and the present-day state of the North African margin. Additionally, we analyze the organization of fracture systems and the movement in term of tensor stress and the evaluation the vulnerable areas. From Paleozoic to the present day, the geodynamic evolution is marked by several stages. Each stage showed a specific structuration related to the paleogeographic evolution of paleotethys, in the western margin of Tethys and the Mediterranean margin. The complex structural pattern of Tunisia resulted from the polyphased Cenozoic reactivation of inherited faults. The existing tectonic and structural information completed by the reconstruction of the succeeded of major tectonic events, allowed better understanding of the seismogenic zone related to the geodynamic African-Eurasia plate boundary. It was concluded that the main source of geodynamic activities in the Northern African plate in Tunisia is essentially caused by inter-plate deformations along major active faults.

Keywords: Keywords: African Margin, Tunisia, tectono, stratigraphy Seismogenic zone.

*Corresponding author Bouaziz Samir

116

event, Active fault,


S.08: SEISMIC WAVE VELOCITY AND GEODYNAMIC EVOLUTION IN NW OF WEST AFRICAN CRATON : CASE OF THE MOROCCAN MESETA ? ATLAS DOMAIN Timoulali Youssef 1, Jabour Nacer 2 1 - Institut scientifique, Université Mohamed V (Morocco), 2 - Institut vational de Geophysique- CNRST (Morocco)

Abstract This study presents the outcomes of the local earthquake tomography applied in NW of West African Craton at the Moroccan Atlas domains. The arrival times data used in this study were obtained by the Moroccan seismic network. The seismic data (P and S wave arrival times) have been collected by 36 seismic stations located in the Atlas?Meseta domain for the period between 1988 and 2010. A linearized inversion technics and 3D modeling are used for determination of local velocity structure. A reconstruction of the geodynamic evolution is made by combining seismic tomography and geochronology. Local earthquake tomography technics allow us to obtain a deep velocity structures in the Atlas ? Meseta domain and accommodated new insights on imaging in detail deep geological structures. Analysis of seismic wave velocity was used to define and mapping main features of deep structure along northern margin of the West African Craton. Geodynamic evolution is discussed based on these deep structures and a geodynamical model is proposed to explain this evolution.

Keywords: Atlas Mountains, Seismic tomography, Lithospheric structure, Geodynamic

*Corresponding author Timoulali Youssef

117


S.08: CONTRIBUTION OF RADAR SATELLITE IMAGES IN RELIEF STUDYING IN THE PROVINCE OF AL-HOCEIMA Boulaassal Hakim 1, Annaki Sara 2, El Kharki Omar 3 1 - Géoinformation et Aménagement du Territoire, FST_Tanger (Morocco), 2 - GAT, FST Tanger (Morocco), 3 - Géoinformation et Aménagement du territoire, FST Tanger (Morocco)

Abstract The main objective of this article is to use the free radar data such as Sentinel1 images, provided by the European Space Agency (ESA), to study the relief of Al-Hoceima province via radar interferometry technique. Two aspects have been studied through this study. The first one consists in exploiting the information contained in the phase of the Sentinel-1 radar images in SLC mode (Single Look Complex) to generate the Digital Terrain Model (DTM). For evaluation, the DEM generated from the Sentinel-1 images was compared to that derived from the SRTM (Shuttle Radar Topography Mission). After analysis, it turned out that the two products are complementary. The second aspect is to use the technique of differential interferometry (DinSAR) to detect the fine movements of the terrain and to create a map of displacement of the ground in the province of Al-Hoceima. This is a study of vertical displacements of soils, subsidence or upwelling. The results obtained by this technique indicate that it is indeed a recovery. These results suggest that this region is in compression, so elevation of soil levels. To validate this observation, it is possible to compare these results with geodynamic data in this region.

Keywords: Sentinel, 1, InSAR, Radar interferometry, DEM, DinSAR, soil displacement.

*Corresponding author Boulaassal Hakim

118


S.08: TROPOSPHERIC WATER VAPOR CORRECTION MODEL FOR INSAR USING ENVISAT/ASAR-MERIS DATA Aguemoune Samir 1, Abdelhakim Ayadi 1, Belhadj-Aissa Aichouche 2, Bezzeghoud Mourad 3 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria), 2 - des Sciences et de la Technologie Houari Boumediène (Algeria), 3 - Universidad de Evora (Portugal)

Abstract SAR (Synthetic Aperture radar) interferometry efficiency depends essentially on the reduction of errors effects. The atmospheric wet delay (AWD) and phase unwrapping play a key role in the interferometric process. This paper addresses a new method for AWD estimation based on ESA-ENVISAT/ASAR and auxiliary MERIS data. Usually this procedure is used under favorable conditions (small spatiotemporal baseline and relatively free-cloud conditions) In our study we focus on the possibility to use MERIS data under cloudy conditions. We propose a new algorithm for interpolation of water vapor in presence of clouds using a hybrid technique called 3D-IDW, based on Inverse Distance Weighted combined with a linear regression model. This method gives more realistic prediction of water vapor distribution in cloudy area by introducing beforehand, an appropriate cloud mask algorithm which reduces the effect of invalid reflectance and mixed pixels. The phase unwrapping method we used is from Aguemoune et al (2014) based on 2Dpseudocorrelation quality map and noncontinuous path unwrapping. Our procedure was tested on the Zemmouri area affected by a strong earthquake on may 21st 2003 Mw6.8 using a couple of ASAR single look complex (SLC) and MERIS level 2 product on the 65 descending track. The results show the existence of subsidence districts in agreement with those obtained in other studies.

Keywords:

Interferometry, interpolation, Synthetic Aperture Radar (SAR), MERIS,

Deformation.

*Corresponding author Aguemoune Samir

119

Poster: Geodynamics, GPS, InSAR and remote sensing https://afsc2018.sciencesconf.org/192968/

S.08: ETUDE ANALYTIQUE DES LINÉAMENTS MORPHOSTRUCTURAUX DU RIF CENTRAL (MAROC) Moussaoui Siham 1, Azzouz Omar 1 1 - laboratoire de géologie appliquée;faculté des sciences;oujda (Morocco)

Abstract La formation de la chaîne du Rif résulte d'une superposition de plusieurs phases de déformations qui se sont succédées depuis l'Oligocène jusqu'au Tortonien. Le façonnement de sa morpho-structure actuelle se rapporte à des mouvements tectoniques récents et actifs de moindres importances régies par la persistance du rapprochement Afrique Europe et les phénomènes épirogéniques des équilibres isostatiques. Cette activité néotectonique est animée par des déformations essentiellement cassantes relevant de la réactivation de toutes les structures géodynamiques préexistantes. Elle se traduit par l'alignement des traits morpho-structuraux, définis par des crêtes, des réseaux hydrographiques et des tracés de côtes. L'étude analytique de ces traits morphologiques nous permet de décrire des systèmes de linéaments bien définis qui se vérifient de manière comparable dans diverses localités. L'expression de ces agencements géométriques est défini vraisemblablement dans une organisation morpho-structurale contrôlée par des déformations essentiellement cassantes. Leur manifestation s'inscrit dans des relais de déformations régie en profondeur par une réactivation des structurations crustales.

Keywords: linéaments, morpho, structurale, rif central

*Corresponding author Moussaoui Siham

120


S.08: SEISMIC ANISOTROPY OF NORTH ALGERIA FROM SHEAR-WAVE SPLITTING ANALYSIS Radi Zohir 1, Yelles-Chaouche Abdelkrim 1 1 - Centre de Recherche en Astronomie Astrophysique et Géophysique (CRAAG) (Algeria)

Abstract There are only few studies of internal deformation under Northern Africa; here we present such a study. We analyse teleseismic shear-wave splitting for the north part of Algeria, which improves our knowledge of lithospheric and asthenospheric deformation mechanisms in this region. The data are from several broadband (BB) stations that have recently been installed in this part of Algeria. This allows us to study waveform data generated by many tens of teleseismic events that were recorded at seventeen broadband stations. These stations cover thus a large area from the Tellian geological units in the North to the Saharian Atlas units in the South. Analysis of SKS-wave splitting results in significant spatial variations in fast polarization orientation, over scale length of 100 km and possibly less. The seismic anisotropy shows three clear spatial patterns observed at the stations. One pattern is a general ENE-WSW orientation observed for the subsurface under the stations in the North. This polarization orientation follows the direction of the Tell Atlas mountain chain, which is perpendicular to the convergence direction between Africa and Eurasia. Delay times vary significantly across the region, between 0.6 and 2 sec. At several stations there is an indication of a WNW-ESE polarization orientation, which is apparently related with a later geodynamic evolution phase of this region. A third pattern of seismic anisotropy emerges in the South, with roughly N-S orientation. We discuss the observations in light of geodynamic models and present-day geodetic motion.

Keywords: northeastern Algeria, anisotropy, Shear wave splitting, deformation

*Corresponding author Radi Zohir

121


S.08: INTERFEROMETRY SAR ANALYSIS OF AL HOCEIMA (MOROCCO) DEFORMATION DUE TO A 6.3 MW EARTHQUAKES ON THE 25/01/2016 USING SENTINEL-1A IW. Muhire Desire 1, Yassine Tounsi 1, Ahmed Siari 1, Hamid Bioud 1, Abdelkrim Nassim 1 1 - Chouaib Doukkali University (Morocco)

Abstract SAR interferometry (InSAR) is an emerging field for the analysis of earth surface deformation with sub-centimeter accuracy. In this paper, we study the region of Al Hoceïma known for its dynamic seismic activity where several earthquakes were measured by the United States Geological Survey (USGS) in 2016 with magnitudes varying from 3.9 to a 6.3 Mw. We generate the interferometric products of the 6.3 Mw measured at 50km NNE of Al Hoceïma on the 25/01/2016 by using Sentinel-1 Interferometric Wide Swath Mode (IW) images, the InSAR processing based on the generic map tool (GMT5SAR) software and QGIS. The deformation map is obtained by the two pass differential InSAR between two SAR images where the master was acquired on January 10, 2016, and the slave on February 15, 2016, and a Digital elevation model by Shuttle Radar Topography Mission is used to remote the topography influence. We observed concentric fringes around the mountain region of Rif, and a high LOS displacement, (min: ?26.8 mm, max: +26.8 mm) regions near the epicenter. Our results are consistent with USGS ground data observation.

Keywords: Sentinel1, Radar, SAR, Interferometry, Deformation, Monitoring

*Corresponding author Muhire Desire

122


S.08: USING MAPPING DATA AND REMOTE SENSING TO GENERATE A 1/100 000 SCALE GEOLOGICAL MAP (AGDZ, MOROCCAN ANTI-ATLAS) Elmortaji Nizar 1, El Kharki Omar 1, Boulaassal Hakim 1, Alaoui Yazidi Otmane 1, Fekkak Abdelilah 2 1 - Faculty of Sciences and Techniques, Tangier (Morocco), 2 - Faculty of Sciences, ChouaïbDoukkali University, El Jadida (Morocco)

Abstract Given its mineral richness, the Moroccan Anti-Atlas had been given a special attention during the National Geological Mapping Program (PNCG). However, most of the geological maps realized cover essentially the Precambrian bedrock, thus the Paleozoic cover still contains several unmapped areas, and some detail work is still needed for some areas already mapped. On the other hand, geologists find multiple problems when realizing geological maps (limited access to exposures, reduced financial means, unfavorable weather conditions ...), which generates a heterogeneity and a discontinuity of the collected information. Remote sensing, with its ability to cover large areas and provide multispectral imagery, has proved its effectiveness in geological mapping at the Anti- Atlas.The aim of this work is using remote sensing to improve geological mapping, and mapping the uncovered areas of the Agdz sheet at a scale of 1/100000, basing on geological maps realized by the PNCG (Bouscour 1/50000 and Timidghas 1/50000), which will serve as a reference to check the lithostratigraphic subdivisions. The results obtained are integrated into a spatial database using spatial DBMS PostGreSQL-PostGIS.

Keywords: Geological mapping, AntiAtlas, Agdz, Remote sensing, Spatial Data Base PostGIS

*Corresponding author Elmortaji Nizar

123


S.08: APPLICATIONS OF MULTISPECTRAL REMOTE SENSING TECHNIQUES TO UPDATE THE GEOLOGICAL MAP OF AL-MAGHRABAH AREA, HAJJAH PROVINCE, YEMEN Alnahmi Fuad 1, Hilali Atika 2, Rhinane Hassan 3, Baidder Lahssen 4, Khanbari Khaled 5 1 - Fuad Al-Nahmi (Morocco), 2 - Atika Hilali (Morocco), 3 - Hassan Rhinane (Morocco), 4 - Lahssen Biadder (Morocco), 5 - Khaled Khanbari (Yemen)

Abstract Remote sensing played an important role in the geological studies, interpretation and update the geological maps, remote sensing help in the collect and interpret of information about an object without physical contact with it. The aim of this study is achievement to update the geological map of the study area. The data utilizes is satellite image Sentinel-2, the processes used in this study, the OIF Optimum Index Factor is a statistic value that can be used to select the optimum combination of three bands in a satellite image. It's based on the total variance within bands and correlation coefficient between bands, PCA Principle component analysis is a statistical method under the broad title of factor analysis. The purpose of PCA is to reduce the large dimensionality of the data space (observed variables) to the smaller intrinsic dimensionality of feature space (independent variables), which are needed to describe the data economically. Sharpening is used to determine the edges and boundary of the lithology units, filtration also used to detect the geological structures like faults, folds, lineament and fractures in the area. The results obtained in this paper show that remote sensing was proved to be an effective tool in update the geological map of the region. Where there is a significant change in the distribution of rock units, structures and geological events compared to the previous geological map. The approach used in this study enables a great potential for lithological mapping, furthermore it gives the chance to update the old maps.

Keywords: Geological map, Sentinel, 2, OIF, PCA, Sharpening, Al, Maghrabah, Yemen

*Corresponding author Alnahmi Fuad

124


S.08: IS THE NUBIA PLATE RIGID OR DIVIDED INTO SUBPLATES? INSIGHTS FROM GEODETIC DATA AND THE SEISMOTECTONIC MAP OF AFRICA Mukandila Ngalula Raphael 1 2, Masson Frederic 1, Meghraoui Mustapha 3 1 - EOST-Institut de Physique du Globe de Strasbourg (France), 2 - Research Center of Geophysics (Congo - Kinshasa), 3 - Institut de Physique du Globe, CNRS-UMR 7516 (France)

Abstract Numerous geodetic studies have been carried out in recent years to characterize the kinematics of the African plate. Previous geodynamic and tectonic studies first led to the separation of the Africa plate into 2 plates, namely the Nubia plate to the west of the East African rift and the Somalia plate to the east. The subsequent densification of GPS data around the rift and related eastern tectonic blocks made it possible to subdivide the Somalia plate into several sub-plates (Somalia, Victoria, Rovuma and Lwandle). Nowadays, the density and quality of GPS data on the Nubia plate allow us to question its rigidity. Indeed, the recent seismotectonic map of Africa (*Meghraoui et al., 2016) shows that major tectonic structures and/or volcanic lines (e.g., Okavango, Cameroun) display significant seismicity and present-day active deformation. Can this seismicity be related to sub-plate boundaries within the Nubia plate? Using a GPS data synthesis and geodynamic analysis, we here question the possibility of defining 3 sub-blocks, i.e., the West Africa block, the Equatorial-central Africa block and the Southern Africa block. The African plate is characterized by geological shield structures made of basement rocks (mainly Proterozoic and Palaeozoic) where the seismotectonic activity and active deformation (inferred from GPS velocities) promote the sub-division and dislocation of the presumably rigid Nubia.

Keywords: Nubia, GPS, seismotectonics, plate tectonics

*Corresponding author Mukandila Ngalula Raphael

125


S.08: APPORT DES IMAGES SATELLITAIRES ET DES MODÈLES NUMÉRIQUES DE TERRAIN À LA RECONAISSANCE ET LA CARTOGRPHIE DES STRUCTURES NÉOTECTONIQUE AU NE DE L'ALGÉRIE Mohammedi Yahia 1 2, Hamidatou Mouloud 2 1 - Université des Sciences et de la Technologie Houari Boumediene [Alger] (Algeria), 2 - Centre de Recherche en Astronomie Astrophysique et Géophysique (Algeria)

Abstract La cartographie des structures néotectonique est l'un des problèmes majeurs dans le domaine de l'évaluation de l'Aléa sismique, cette cartographie se fait auparavant par des techniques classiques comme le recours aux photos aériennes. Dans le cadre de ce travail on présente quelques applications des techniques de la télédétection moderne à la cartographie des structures potentiellement actives dans la zone de Constantine et ses alentours. Pour arriver à cet objectif on a utilisé les images satellitaires LandSat 8, Eo Ali et Orbview, ces images ont été rehaussées par un certain nombre de traitement et analyse pour extraire de l'informations structurales de façon rapide (ex: ACP, Filtrage, composions en fausses couleurs.). Cette analyse a été complété par une étude morphotectonique par le recours aux modèles numériques de terrain SRTM 30 et par l'analyse des formes de reliefs caractéristiques de la tectonique active. Les résultats de ce travail ont été synesthésie dans des cartes sismotectoniques qui contiens toutes les structures cartographiées avec une superposition de la sismicité de la zone. Toutes les données obtenues au cours de ce travail ont été intégrées dans une base de donnée SIG.

Keywords: Structures néotectonique, SRTM30, LandSat, télédétection, Algérie

*Corresponding author Mohammedi Yahia

126


S.08: LAND USE/LAND COVER IN SAISS PLAIN, USING REMOTE SENSING TECHNIQUES El Hafyani Mohammed 1, Essahlaoui Ali 1, Mohajane Meriame 1, El Ouali Abdelhadi 1, El Hmaidi Abdellah 1, Van Rompaey Anton 2 1 - Université de Moulay Ismail (Morocco), 2 - Catholic University of Leuven (Belgium)

Abstract The Saiss plain located in the center of Morocco, is one of the very important areas for agricultural practice with acceptable soil quality and a very large quantity of water resources. Recently, the management of these resources is unsustainable, on the one hand the overexploitation of water resources due to population growth and the development of industry, and on the other hand, the urban extension in agricultural areas, which offers a wide study to give and propose solutions to these problems. In this work, our main objective is to study land use/land cover changes in the Saiss Plain during the last 30 years, using remote sensing techniques based on the processing of satellite images with high spatial resolution. The multi-temporal maps of vegetation, soil, and soil moisture surfaces are created based on the analysis of spectral index; NDVI (Normalized difference Vegetation index), NDSI (Normalized difference soil index), and NDWI (Normalized difference Water index), using 4 Landsat TM images and one Landsat Oli Image acquired respectively in 1884, 1995, 2003, 2009, and 2017. The results show a decline in the vegetation surface of 83.97%, from 53381.52 ha in 1984 to 8559.47 ha in 2017, the soil surface decreased by 81.5% from 88510.61 ha to 15978 ha, and water surface has increased by 86.16% in the same period.

Keywords: Saiss plain, remote sensing, spectral index, NDVI, NDSI, NDWI.

*Corresponding author El Hafyani Mohammed

127


S.08: GEODYNAMIC EVOLUTION OF BOUKAÏS-EL AHMER AREA (NORTH BECHAR, SW ALGERIA) : USING REMOTE SENSING AND FIELD DATA Chabane Sarah 1, Amri Kamel 1, Hamdidouche Rachid 1 1 - Université des Sciences et de la Technologie Houari Boumediene [Alger] (Algeria)

Abstract The study area, extending from Boukaïs, to the West, to the western limit of Djebel Horeit to the East and from Ménabha to the North to El Ahmer village to the South. It is located at 40 km North of the city of Bechar in the Southwestern part of Algeria. The outcropping paleozoic formations are Cambrian to Carboniferous of age. The situation of this zone is complex regarding its position between two branches of the Southern Atlasic Fault. This major fault goes by the Boukaïs-Béni Zireg-Béni Ounif axis which seperates the Saharan Plateforme from the Occidental Saharan Atlas. The Boukaïs-El Ahmer formations are strongly deformed where the Devonian limestones remain the most affected.The results of the remote sensing analyses on « Landsat 7 ETM+ » and « Landsat 8 OLI » allowed us to discriminate the different lithologies and to draw a lineament map in which all the supposed fault trends are presented and which are confirmed by field data. In this study, we discuss the different constraint directions obtained by analyese of field data and present the different stages of the deformation since the Paleozoic.

Keywords:

The paleozoic, Boukaïs, El Ahmer, North Bechar discriminate the different lithologies, lineament map, analyese of field data.

*Corresponding author Chabane Sarah

128


S.08: ESTIMATION OF LAND DEFORMATION IN OILFIELDS BY MEANS OF DINSAR, CASE STUDY IN-SALLAH, ALGERIA Smail Tayeb 1, Abed Mohamed 1, Fatma Canaslan çomut 2 1 - Université de Blida 1, Faculté de Technologie (Algeria), 2 - Disaster & Emergency Directorate of Denizli (Turkey)

Abstract The vertical deformation of surface at In Salah Gasfield is caused in part by the injection of CO2 and the production of Gas, The CO2 storage project has been in operation since 2004 with three horizontal wells into the water leg of the Krechba Carboniferous Sandstone gas producing with a reservoir thickness of 20m, and 1900 meters of depth. the amount of CO2 injected at the end of 2008 was 2.5 million tonnes. Its effects is clearly visible and it is produce a deformation signature at the earth's surface. The analyses of several data over In Salah Gasfield show a general trend of subsidence and uplift from the C band ENVISAT satellites.

Keywords: DInSAR, Deformation, Oilfield

*Corresponding author Smail Tayeb

129


S.08: MEASURING DEFORMATION DUE TO 2016 NEW ZEALAND MW7.8 EARTHQUAKE BY USING GNSS PRECISE POINT POSITIONING TECHNIQUE Allal Saddam Housseyn 1, Dekkiche Hichem 2, Bouguern Abderrahmane 3 1 - Space Techniques Centre and Earth Physics Laboratory of University of M'Hamed Bougara (Algeria), 2 - Department of Space Geodesy, Space Techniques Centre, Algerian Space Agency (Algeria), 3 - Earth Physics Laboratory, Faculty of Hydrocarbons and Chemistry, University of M'Hamed Bougara (Algeria)

Abstract The main objective of this work is to evaluate the contribution of the GNSS (GPS & GLONASS) positioning technique in PPP (Precise Point Positioning) mode to study the coseismic displacements of 2016 New Zealand Mw7.8 earthquake. Relaxation of the coseismic stresses following an earthquake causes post-seismic crustal deformation, which may remain for days to years. Continuous monitoring of post-seismic deformation facilitates the understanding of the mechanism of deformation and post-seismic relaxation and viscous rheology. This work focuses on the processing of GPS and GLONASS observations with RTKLIB 2.4.2 software, developed at the University of Marine Science and Technology in Tokyo, Japan. Data of 182 stations of the permanent GNSS network GeoNet (Geological hazard information for New Zealand) are used. Positions time series analysis shows that four (04) stations (CMBL, KAIK, WITH and HANM) underwent a large displacement during the earthquake. The maximum is observed at the CMBL station, the displacements along the three directions (Northing, Easting and Up) are 2.28 m, 1.21 m and 0.88 m, respectively. These results show that the PPP method can be used successfully to estimate coseismic deformations caused by large earthquakes.

Keywords: GNSS PPP Timeseries Deformation NewZealand

*Corresponding author Allal Saddam Housseyn

130

Poster: Education, Outreach & Communication https://afsc2018.sciencesconf.org/192284/

S.09: THE IMPACT OF CLIMATE CHANGES IN THE WATER RESOURCES IN THE PLAIN OF THE GHARB (WESTERN NORTH OF MOROCCO) El Houyr Said 1, Kachtali Mohammed 1 1 - Université Ibn Tofaïl (Morocco)

Abstract Climate change is currently one of the phenomena that threatens both human societies and ecosystems in many countries around the world. Morocco, given its situation in the North West of the African continent, bordered by two maritime facades, is among the most vulnerable countries to the effects of climate change. Studies and simulations predict that this will have adverse consequences for the environment, particularly on surface and groundwater resources. This is due to the increase in temperature and the great variability of rainfall and the continuous increase in water demand. The Gharb plain, considered one of the most important water reservoirs in Morocco, is at the same time the largest irrigated perimeter of the country, from the agrarian point of view. Nowadays, this space has become fragile because of overexploitation and the effects of climate change increasingly threatened it. The objective of this study was to investigate the relationship between climate changes and the water resources on the Gharb plain. This relationship expressed through two different types of impacts: on the one hand, the plain has affected by the lowering of the water table and on the other hand, it suffers the adverse effect of floods. To explain this complex situation, we have called for statistical indicators relating to climate and hydrology of the plain and to cartographic modeling using multifactorial analysis. This approach has led to the following preliminary results: from a statistical point of view, the Gharb plain has experienced, in recent years, succession of repetitive droughts periods and rainfall abundance periods. These results have led to a downward trend in the groundwater level due, in particular, to the agrarian intensification. Despite the state's efforts to limit this phenomenon, this situation of climatic irregularity has often led to catastrophic floods in Gharb.

Keywords: Climate change, water resources, cartographic modeling, drought.

*Corresponding author El Houyr Said

131


S.09: IDENTIFICATION SISMIQUE DE LA STABILITÉ D'UN BÂTIMENT DANS LA MULTI-PHASE NON LINÉAIRE PAR UN SYSTÈME DE CONTREVENTEMENT DE FRP Taoufik Tbatou 1, Elyoubi Mohamed 2 1 - Ensa (Morocco), 2 - EMI (Morocco)

Abstract Aujourd'hui, dans le domaine de la construction, la prise en compte des problèmes dynamiques est nécessaire pour garantir la fiabilité des structures dans les différentes applications, notamment dans le cas des structures soumises aux sollicitations sismiques. L'intérêt de ce travail est d'étudier les effets des matériaux composites utilisés dans le concept du contreventement pour un bâtiment sous le cadre des méthodes de dimensionnement en déplacement. En effet, un ensemble des bâtiments en béton armé, conçus en respectant les pratiques parasismiques usuelles, est utilisé de façon à étudier l'influence du contreventement, à base des plaques innovantes (FRP) par rapport celle du voile en béton armé, sur la stabilité de l'ouvrage lors d'un séisme. Plusieurs simulations numériques sismiques ont été conduites à fin d'identifier l'intérêt de différentes variantes à travers les indicateurs de dégradations partielle et totale de la superstructure.

Keywords: Séisme, stabilité, bâtiment, contreventement, dégradation, plaque FRP

*Corresponding author Taoufik Tbatou

132


S.09: THE EDUCATIONAL SEISMIC STATION PRINCESS LALLA AICHA OF AGADIR El Kilali El Hassan 1, Es-Saady Youssef 1 1 - Association Sciences of Life and Earth Souss (ASVTS) - Ibn Batouta School (Morocco)

Abstract The Association for Life and Earth Sciences Souss (ASVTS) is a regional NGO created in 2002 in Agadir, Morocco. Active in the fields of environmental education and sustainable development, ASVTS started in 2013 a strategic project: A seismic station for educational purposes in Agadir. Its main objective is to inform and educate citizens about earthquakes and behaviors to adopt in seismic emergencies. Princess Lalla Aicha Stattion was therefore the first of its kind in Africa, in this city known for high seismic hazard. The earthquake of Agadir on February 29, 1960 (5.7 on the Richter scale), is considered the biggest natural disaster in Morocco in modern era with 12000 to 15000 victims, 25000 wounded and 90% of the city destroyed. After the disaster, the state made substancial efforts to reconstruct the city of Agadir. But the seismic risk is always there and from time to time, small tremors remind the inhabitants of the threat. Considering this reality, ASVTS and its partners have developed the project of the educational seismic station Princess Lalla Aicha. In five years, the objectives have been defined: to sensitize citizens to the natural phenomenon, to make the young "ambassadors" of the behavior that saves, to provide institutions with scientific and pedagogic support ... The station is operational and receives citizens of all ages and socio-professional backgrounds for sensitization, popularization of scientific sessions. To share this experience and its achievements, and to extend the horizon of our action with other insights, the meeting of Al-Hoceima is an opportunity for our seismic station to establish African ties.

Keywords: educational seismic station, Agadir

*Corresponding author El Kilali El Hassan

133


S.09: INDICATORS IN RISK MANAGEMENT : A FRESH PERSPECTIVE BETWEEN HAZARD ANALYSES AND SOCIETIES' RESPONSES Ivcevic Ante 1 2, Mazurek Hubert 3, Siame Lionel 4 1 - Laboratoire Population-Environnement-Développement (France), 2 - Centre européen de recherche et dénseignement de géosciences de lénvironnement (France), 3 - Laboratoire Population-Environnement-Développement (France), 4 - Centre européen de recherche et d'enseignement de géosciences de l'environnement (France)

Abstract To better assess the impact of natural risks (as earthquakes, but especially climate change impacts as landslides, marine submersions, floods...) on the environment and human societies, both the physical geological and socialeconomical sciences need strong synergies and interdisciplinary collaborations. This strong impetus will not only improve the understanding of environmental responses to natural and anthropological forcing factors but also strengthens risk assessment by establishing vulnerability indicators and societal resilience. Scientific researches on natural hazards that cross physical, environmental and social approaches are rare. In general, they often consist in a linear succession of different methodologies and analytical documents (hazard description, map of the risk, vulnerability maps, perception study) without a real integration of these different parameters in a global approach that is comprehensive for everyone. Risk is, however, a very cross-sectional domain because there is risk and vulnerability only if there is a potential impact on society. The scientific interest, and innovative part, of this thesis lies in the possible renewal of the concepts of each involved discipline and in a cross modeling of indicators that will allow the emergence of new problematic. This PhD thesis will mainly focus on Northern Morocco (Tangier-Tetouan). This region is characterized by high demographic and economic pressures (port and tourist infrastructures), which exacerbate the vulnerability of the coastal hazards (e.g., landslides, coastal erosion, floods). Lowering the buffering capacity of the beaches and dunes to climate variability, these pressures will necessarily negatively impact on any further coastal development. This PhD thesis aims at identifying reliable risk indicators and societal responses related to multiple risks (natural risk and climate change impacts) in order to provide a governance framework for the prevention of natural hazards in Morocco.

Keywords: risk, indicators, environement, hazard, society

*Corresponding author Ivcevic Ante

134


S.09: CURRENT STATUS OF THE ISC BULLETIN Shumba Blessing 1 1 - International Seismological Centre (United Kingdom)

Abstract The International Seismological Centre (ISC) was set up in 1964 to continue the work of ISS and BAAS. The main mission of the ISC is to analyse and distribute the Bulletin of earthquakes and other seismic events, which serves as the definite summary of global seismicity. To produce the Bulletin, the ISC collects parametric seismic data in the form of hypocentres and seismic phase arrival times, amplitudes and periods from over 150 agencies around the globe from both permanent and temporary seismic deployments. The ISC bulletin is the longest continuous, reliable uniform set of bulletin data. In addition to the global seismic bulletin production, the ISC is actively involved in important additional products and services, which include the ISC-GEM Global Instrumental Earthquake Catalogue, the ISC-EHB bulletin, the International Seismograph Station Registry, the IASPEI Reference Event List (GT), the ISC Event Bibliography, and the International Registry of Seismological Contacts. This presentation focuses on the current status of the ISC Bulletin, with special emphasis on collection of data from the African continent.

Keywords: ISC Bulletin, Global Seismicity

*Corresponding author Shumba Blessing

135

Alphabetical Index of Presenting Authors A

Aassoumi Habiba Abacha Issam Abdel-Aal Abdel-Aziz Abdelouafi Abdallah Abed Mohamed Aberkan M'hamed Aboumaria Khadija Abtout Abdeslam Afilal Tribak Abdelghani Aguemoune Samir Aidi Chafik Aini Djamel Aissa Saoussen Ait Brahim Lahsen Aitelghazi Abdellah Al Amin Ezat Al Makkassi Fatima Ezzahrae Alaoui Yazidi Otmane Allal Saddam Housseyn Allali Sid Ahmed Al-Mahfadi Afrah Alnahmi Fuad Alonso Belén Amadio Claudio Amar Mohamed Ammar Abdellah Amponsah Paulina Amri Kamel Amri Kamel Andriamiranto Raveloson Angel Ciberia Annaki Sara Araújo A. Alexandre Atalay Ayele Ateba Bekoa Athmouni Malak Ayadi Abdelhakim Azguet Roumaissae Azougay Abdellah Azzouz Omar

B

Baby Patrice Badreldin Hazem Bahrouni Nejib Baidder Lahssen Bakkali Saad Barazangi Muawia Bekri Hachem Beldjoudi Hamoud Belhadj-Aissa Aichouche

136

74, 35, 12, 13, 27, 69, 99, 100, 129, 11, 18, 51, 55, 18, 50, 51, 55, 57, 58, 103, 105, 109, 70, 119, 104, 52, 39, 27, 82, 114, 36, 106, 111 123, 130, 99, 72, 124, 8, 80, 106, 110, 37, 41, 108, 17, 128, 25, 60, 106, 118, 32, 3, 86, 108, 90, 6, 21, 98, 119, 37, 48, 95, 8, 14, 120, 4, 38, 75, 124, 46, 2, 76, 30, 54, 119,

Belhai Djelloul, 17, 22, Bellik Amar 107, Ben Sari Driss 2, Benaissa Zahia 28, 33, Benamri Sofia 18, 51, 55, Benbakhti Imene Meriem 22, Benchekroun Sabah 56, Benchelha Said 102, Benchelha Taoufik 102, Bendik Rebbeca 2, Bendjama Hichem 35, Benfadda Amar(3) 39, Benhamouche Azzeddine 59, Benmakhlouf Mohamed 8, Benouar Djilali 81, Bensalmia Ahmed 114, Bernard Paul 108, Beslier Marie-Odile 104, Bezzeghoud Mourad 21, 32, 39, 119, Bioud Hamid 122 Borges José 32, 34, 39, Bouaziz Samir 75, 78, 116, Boughacha Mohamed Salah 39, 98, Bougrine Amina 107, Bouguern Abderrahmane 130, Bouhadad Youcef 16, 17, Boukerbout Hassina 103, Boulaassal Hakim 118, 123, Boulahia Oualid 35, Boulanouar Abderrahim 31, Bourhili Amine 79, Bouskri Ghizlane 37, 48, Bouyahiaoui Boualem 103, 109, Brandt Martin 91,

C

Calais Eric Caldeira Bento Canaslan çomut Fatma Carvalho Joao Casas David Catalán Manuel Cavalié Olivier Cetin Esra Chaaraoui Aboubakr Chabane Sarah Chabane Souhila Chaieb Ali Chalouan Ahmed Chami Adel Chennaoui Hassnaa Cherif Seif Eddine Chimouni Redouane

107, 32, 34, 39, 129, 39, 8, 8, 4, 89, 45, 95, 128, 96, 78, 8, 33, 102, 69, 39,

Chindandali Patrick R.n. Chlieh Mohamed Chourak Mimoun D'acremont Elia Dahaoui Mohammed Dahy Sayed Dakki Mohamed Davila Jose Dekkiche Hichem Delouis Bertrand Delvaux Damien Déverchère Jacques Dhaha Faouzi Dias Rui Dib Assia, Djenba Samir Dobrynina Anna Dridri Abdallah Durrheim Raymond

D

E

El Abassi Mourad El Fellah Younes El Gabry Mohamed El Hafyani Mohammed El Hmaidi Abdellah El Houyr Said El Khalidi Khalid El Kharki Omar El Kilali El Hassan El Mahsani Abderrahman El Mehdi Monsour El Moudnib Lahcen El Moussaoui Said El Mrihi Abdelaziz El Ouai Driss El Ouali Abdelhadi El Tahir Nada El Talibi Hajar Elkailech Youssef Elkenz Abdellah Elmortaji Nizar Elyoubi Mohamed Emran Anas Ercilla Gemma Es-Saady Youssef Essahlaoui Ali Estrada Ferran Ezomo Friday Fadil Abdelali Fadil Abdelhamid Fajri Zainab Faried Ahmad M. Farouk Mohamed Fathi Badr-Eddine Fekkak Abdelilah Fiama Sylvanos B. Floyd Michael, Fontiela Joao

F

67, 4, 8, 45, 69, 95, 8, 13, 36, 72, 2, 110, 130, 30, 85, 88, 105, 75, 39, 21, 20, 31, 83, 25, 29, 60, 88, 91, 76, 37, 48, 49, 19, 53, 80, 127, 76, 127, 131, 79, 102, 118, 123, 133, 13, 27, 82, 112, 5, 50, 51, 55, 57, 58, 94, 26, 76, 127, 92, 50, 51, 55, 57, 58 79, 106, 123, 132, 73, 113, 8, 133, 40, 76, 127, 8, 66, 106, 110, 111 112, 57, 61, 61, 70, 123, 85, 2, 110, 32, 39,

Fourie Christoffel Franco Vaccari

101, 41,

G

Galindo-Zaldivar Jesus Ganza Gloire B. Gil Antonio José Gomez Francisco Gorini Christian Guessoum Nabila

H

Hakdaoui Sofia Hakdaoui Mustapha Hamai Lamine Hamdache Mohamed Hamdidouche Rachid Hamidatou Mouloud Hamoudi Mohamed Haou Youssef Harbi Assia Harnafi Mimoun Hassan Hany Hassoup Awad Havenith Hans-Baalder Hayashida Takumi Hilali Atika Hosny Ahmed Hussein Hesham Idris Mouloud Ito Takatoshi Ivcevic Ante

I

8, 85, 8, 2, 8, 16, 73, 113, 102, 104, 105, 87, 128, 93, 126, 21, 94, 10, 31, 37, 48, 106, 110, 80, 24, 85, 42, 124, 61, 63, 19, 42, 53, 39, 25, 134,

J Jabour Nacer Jele Vincent

9, 117, 64,

K Kachtali Mohammed 131, Kadiri Umar 66, Kariche Jugurtha 52, 89, 98, Khald Hassan 94, Khanbari Khaled 124, Khelif Mohamed Fadhlallah 28, 33, Kherroubi Abdelaziz 30, 54, Kijko Andrzej 101, King Robert, 2, 110, Korchy Hanan 55, Korrat Ibrahim 19, 53, Koulali Achraf 2, 110, Ksentini Ahmed 62, 84, 90, Kwadiba Tarzan 15, 64, 65, 115,

L

Labraimi Ayoub Lallout Imane Lambarki Drissi Ibtissam Lamdouar Nezha Lamine Hamai

13, 27, 11, 40, 104,

137

Layadi Khalissa Lazzar Ayoub Le Pourhiet Laetitia Lewi Elias Liebenberg Bennie Lukindula Jeanpy

47, 77, 105, 2, 25, 88,

M

Maamri Ridha Mahsas Abdelhakim Mahyoub Sulaiman Makkaoui Mohamed Maklad Mohamed Mantsha Reuben Manzi Musa Manzunzu Brassnavy Maouche Said Marimira Kwangwari Maritinkole Joseph Masson Frederic Mavonga Tuluka Georges Mazurek Hubert Mazzotti Stephan Mbossi Eddy Ferdinand Mcclusky Simon Mebarki Ahmed Meghraoui Mustapha

75, 107 112, 14, 42, 64, 25, 29, 64, 91, 10, 17,19,22,53 64, 68, 15, 125, 88, 134, 110, 86, 2, 99, 100 1, 6, 19, 52, 53, 89, 98, 108, 115, 125 Mercier Jean-Luc 58, Merzougui Wissem 75, Midzi Vunganai 29, 43, 64, 91, 92, 101, 115, Mohajane Meriame 127, Mohammedi Yahia 126, Morad Taher 23, Mostafa Shaimaa 12, Moukchane Mohamed 74, Mourabit Taoufik 106, 110, Moussaoui Siham 120, Mphepo Felix 68, Mpuang Admore 15, 65 Muhire Desire 122, Mukandila Ngalula Raphael 125, Mulabisana Thifhelimbilu 43, 64, 115, Myendeki Sinovuyo 7,

N

Naiji Zakariae Nana Gaelle Vanessa Nassim Abdelkrim Nassim Hellal Nobuoto Nojima Noura Hichem Ntibinyane Onkgopotse

O

Ogasawara Hiroshi Ogubazgi Ghebrebrhan Oliveira Rui Omar Khaled Omira Rachid Onstott Tullis

138

Ouallali Abdessalam Ouazani Touhami Abdelouahed Ouchen Ibrahim Oujidi Mostafa Ousmana Habiba Oussadou Farida Ouyed Merzouk Palomino Desiree Panza Guliano Pazos Antonio Pelaez Jose Petit Carole Pule Tebogo

74, 94, 37, 77, 95, 76, 21, 39,

P

R

Rabaï Ghilles Radi Zohir Rahmouni Abdelaali Rathod Ganesh Raveloson Andriamiranto Rebai Noamen Reilinger Robert Rekik Dhouha René Guiraud Rengel Juan Rezouk Ahmed Rezqi Halima Rfifi Mohamed Rhinane Hassan Rimi Abdelkrim Rindraharisaona Elisa Ritz Jean François Romanelli Fabio Romdhane Najla

8, 41, 110, 45, 105, 64, 101, 115 22, 121, 31, 64, 60, 78, 2, 106, 110, 62, 17, 8, 17, 77, 95, 82, 112, 114, 124 110, 60, 17, 22, 80, 84,

S

77, 97, 122, 93, 69, 100, 15, 65,

Sadiki Abdelhamid 71, Sage Françoise 109, Salah Boughacha Mohamed 39, Salama Asem 19, 53, Saleh Mohamed 115, Sanz De Galdeano Carlos 8, Saunders Ian 64, 91, 115, Sayed Mohamed 80, Serroukh Mostafa 94, Shumba Blessing 68, 135, Siame Lionel 134, Siari Ahmed 121, Sigurjon Jonsson 2, Sitali Mako 64, Smail Tayeb 129, Smailhodzic Hrustem 44,

25, 2, 32, 36, 50, 25,

Tabane Leonard Tadili Ben Aissa Tadili Mehdi Tahayt Abdelilah Tahouri Jad Tahouri Ouassim

T

64, 26, 82, 26, 2, 106, 110, 71, 83, 83,

Tavera Hernando Tbatou Taoufik Tenzer Robert Terki Toufik Tharwat Abdelfattah Timoulali Youssef Tladi Bruno Tlemcani Mohammed Tokam Alain-Pierre Touati Mohammed Toussaint Renaud

V

Van Aswegen Gerhard Van Der Meijde Mark Van Rompaey Anton Van Wettum Arie Vazquez Juan Tomás Vernant Philippe Villegas Lanza Juan Carlos

4, 132, 111, 107, 42, 37, 48, 89, 117, 65, 27, 82 97, 40, 89, 64, 65, 127, 65, 8, 2, 110, 4,

Vitres Renier Wachilala Piedade Wahbi Meriam Wassmer Patrick

2,

W

34, 70, 58,

Y

Yabe Yasuo 25, Yakubu Tahir 66, Yalaoui Rafik 39, Yassine Tounsi 122, Yelles Chaouche Abdelkrim 30, 54 Yokoi Toshiaki 42,

Z

Zaghloul Mohamed Najib Ziegler Martin Zourarah Bendahhou Zulu Brian

18, 55, 58 25, 79, 29, 64,

139

Acknowledgement The Organizing Committee would like to thank its partners for their support

Official partners:

Gold partners:

Other partners:

Abstract Book of the 2nd General Assembly for the African Seismological Commission Edited by Mourabit, T., El Talibi, H., El Moussaoui, S. & El kharki, O. Published by Faculty of Sciences and Techniques of Al Hoceima Al Hoceima 04/2018 Cover, Design and Typeset by El Moussaoui S., Printed at Al-Hoceima (Morocco) Number of copies: 150 First Edition ISBN 978-9920-35-173-7