Preliminary tsunami hazard map for Africa
- PDF / 2,007,345 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 102 Downloads / 175 Views
ORIGINAL PAPER
Preliminary tsunami hazard map for Africa Asem Salama 1
&
Mohamed ElGabry 1 & Mustapha Meghraoui 2 & Hesham Hussein Moussa 1
Received: 19 March 2020 / Accepted: 11 September 2020 # Saudi Society for Geosciences 2020
Abstract Major earthquakes display a significant tsunamigenic seismic activity (with Mw > 7) that may affect Africa continent. These events are from the far-field tectonics plates or even nearby tectonics boundaries. The main target of this study was to choose the most dangerous tsunamigenic zones according to the historical tsunami events and to update the tsunami hazard map of Africa published in UNISDR (2009). This was done by using nested bathymetry grids to reevaluate the maximum wave height using high-resolution (15 arcs per second) data near the African coastlines. Mirone version 2.10 software is used in these calculations. Four tsunamigenic zones sources affecting the African coastal zones have been tested at Andaman-Sumatra subduction zone, Makran trench zone, Western and Eastern Hellenic arcs. These tsunamigenic source zones were responsible for huge tsunamis generated from large historical earthquakes on 26 December 2004; 27 November 1945; 8 August 1303; and 21 July 365. Two to 4 m was the calculated maximum wave height resulted from the scenario 1 which arrived to the coasts of Tanzania, South Africa, and South Madagascar, while scenario 2 resulted in maximum wave height of 1–2 m toward the Somalian coast. The scenarios 3 and 4 were responsible for the maximum wave height of 2–4 m at the Egyptian and Libyan coasts. Preparing an early warning system will be required necessarily for the whole of Africa to overcome possible future high tsunami risk to the African coastal cities. Keywords African tsunamis . Modeling . Tsunami hazard map
Introduction Tsunamis are natural hazards that can trigger severe disasters. In the last 30 years, more than 290 tsunamis were observed worldwide (Gusiakev et al. 2019). Around 250 thousand deaths resulted from two transoceanic tsunamis: 2004 Indian Ocean and 2011 Tohoku (Synolakis et al. 2007; Aida et al. 2017; Gusiakev et al. 2019). Many lessons were gained from these two significant events, aiming to provide understanding, detecting, and mitigation of the impacts of tsunamis,
This article is part of the Topical Collection on Seismic Hazard and Risk in Africa * Asem Salama [email protected] 1
National Research Institute of Astronomy and Geophysics, Helwan, Cairo 11421, Egypt
2
EOST-Institute de Physique du Globe-CNRS-UMR7516, Strasbourg, France
especially from far-field tsunamigenic sources. Large earthquakes and tsunamis have affected the coastal areas along the African continent (Okal et al. 2009). Løvholt et al. 2009 used numerical modeling to predicate the sources, amplitude which could affect the South African zone. The results of this study were published as a tsunami hazard map of Africa (UNISDR report 2009). Recently, Aniel-Quiroga et al. 2018 obtained 50 average profiles of bathymetry data using the coupling of two num
Data Loading...
