Preliminary tsunami hazard map for Africa

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.