Reappraisal of tsunami hazard for the Northern Coastal of Egypt considering sea level rise and delta subsidence scenarios

In this research, we have compiled a catalogue of the worst tsunami earthquakes that caused destruction and losses in the northern coastal region of Egypt. Variability in seismic source parameters reflects the level of cognitive uncertainty that exists because most of these destructive tsunamis, if not all, occurred in the pre-instrumental period. We also synthesized a set of hypothetical tsunamis constrained by seismotectonic knowledge of the area of influence to embrace the uncertainty. We also collected the topo-bathymetry information available to make a simulation on the scale of the Egyptian north coast. The multiple scenarios were computed considering references and hypothetical scenarios, and results were presented in maps and tables for wave heights, inundation depth, and estimated arrivals. Comparisons were made between the results calculated in this study and those from previous studies. These were done to identify and measure the reasons for the difference and similarities. The results may contribute to developing risk reduction strategies and a national early warning system. Variability in tsunami intensity measures is prepared for the hypothetical scenarios due to the difference in the fault’s magnitude, location, and geometry. Also, for the first time, temporally based scenarios the sea-level rise and delta sinking were considered in order to highlight the importance of multi-risk analysis for the region of interest. The insight on incorporating other hazards of the temporal resolution indicates a significant increase in inundated areas and wave height. Therefore, proper and detailed estimation of multi-hazard maps for the coastal region of the Nile Delta is highly required to protect the ongoing sustainable development and protect the people and their assets.