Probabilistic analysis of potential ground motion levels at the principal cities in Upper Egypt

Abstract

In this study probabilistic methods have been applied for the estimation of ground motion severity at selected sites in 8 principal cities in Upper Egypt. A new comprehensive updated earthquake catalog is compiled from a variety of sources. It includes all earthquakes that occurred in Upper Egypt and adjacent regions in the period from 1900 to 2001. Seismic hazard estimates are derived from regional seismogenic zones that are based on interpretations and assumptions relating potential seismic activity to the seismotectonics of the region. The expected values of the horizontal component of PGA with 90 percent probability of not being exceeded in 50, 100 and 200 years of exposure period are calculated. Among the selected sites the highest potential ground motion is found at Aswan and Hurghada, while the lowest is at Luxor. A further seismic hazard curves for the selected sites are designed. The highest potential ground acceleration level is also found at Aswan and Hurghada, which are located relatively near to the Kalabsha area and Shadwan area respectively, where the seismic activity in both areas are considered relatively high, while the lowest is at Luxor and Assuit. Since these areas are proposed for development, application of these methods results in an honest representation of probabilities of earthquake ground shaking or other earthquake hazard can be used to make informed decisions on mitigating earthquake risks in the presence of uncertainty.