Citation

Bouhadad Y, Laouami N. Nat. Hazards 2002; 26(3): 227-243.

Copyright

(Copyright © 2002, Holtzbrinck Springer Nature Publishing Group)

DOI

unavailable

PMID

unavailable

Abstract

This paper deals with the probabilistic seismic hazard analysis carried out in the Oran region, situated in the Northwest of Algeria. This part of Algeria was historically struck by strong earthquakes. It was particularly affected during the October 9, 1790 Oran earthquake of intensity X. The main purpose of this work is to assess seismic hazard on rocks in order to provide engineers and planners with a basic tool for seismic risk mitigation. The probabilistic approach is used in order to take into account uncertainties in seismic hazard assessment. Seismic sources are defined in the light of the most recent results obtained from seismotectonics analyses carried out in North Algeria. Source parameters such as b-values, slip rate and maximum magnitude are assessed for each seismic source. The attenuation of ground shaking motion with distance is estimated by using attenuation relationships developed elsewhere throughout the world (Sadigh et al., 1993; Ambraseys and Bommer, 1991). The two relationships agree well with the local data. Different choices of source parameter values and attenuation relationships are assigned weights in a logic tree model. Results are presented as relationships between values of peak ground acceleration (PGA) and annual frequency of exceedance, and maps of hazard for return periods of 200 years and 500 years. A maximum peak ground acceleration of 0.42 g is obtained for the Oran site for a return period of 500 years.

Language: en