Understanding Extreme Geohazards: The Science of the Disaster Risk Management Cycle European Science Foundation Conference November 28 to December 1, 2011, Sant Feliu de Guixols, Spain

Updating Seismic Hazard Approach: Application to New Metropolitan Area

Abd el-aziz Abd el-aal
National research institute of astronomy and geophysics, Department of seismology, Helwan, 11722 Cairo, Egypt, dewaky@yahoo.com

In this contribution, updating seismic hazard procedure is used to estimate seismic hazard at new metropolitan area at Aswan, Egypt. Seismic activity on Aswan Area, which includes five active faults named Kalabsh, Seiyal, Gabal El-Barqa, Kurkr, and Khor El-Ramla fault system, has increased during the last decades with many strong events. These earthquakes resulted in major stress-drops on the western side of the Naser Lake. These fault segments were recently explored using bathymetric and reflection surveys. These recent findings helped to reshape the seismotectonic environment of the Aawan area which is a perplexing tectonic domain. Based on collected new information, seismic hazard of the Aswan region, particularly New Aswan Metropolitan Area and its vicinity were re-examined using a probabilistic and deterministic approaches. Alternate seismic source and magnitude-frequency relations combined with various indigenous and “foreign” attenuation relationships were adapted within a logic tree formulation to quantify and project the regional exposure on a set of hazard maps. The hazard maps show the peak horizontal ground acceleration and spectral acceleration at 1.0 sec. These acceleration levels were computed for 2 and 10 percent probabilities of being exceeded in 50 years.