Seismic Hazard Assessment for the Main Seismogenic Zones in North Algeria

Abstract

A seismogenic zoning for north Algeria is proposed. The characteristics of each zone are studied in detail and different statistical analyses are performed in order to assess the slope of the Gutenberg-Richter relationship, the mean annual activity rate of earthquakes, the average return period, the probability of non-exceedence during a time period and the maximum expected magnitude. The slope of the Gutenberg-Richter relationship determined by traditional methods, physical strain energy release and corresponding magnitude, together with a new approach based on both historical and instrumental data, are used to estimate the seismic hazard parameters.The seismic hazard parameters obtained described well the characteristics of each proposed seismogenic zone. The b-value of the Gutenberg-Richter relationship concurs especially well with the most common seismotectonic interpretation of each zone, for example 0.70 9 0.06 at El Asnam region and 0.639 0.09 around Algiers. The average return period obtained (approximately 300 years for magnitude 7.5 at El Asnam region, exceeding 1000 years in other regions), corroborate those obtained through Paleoseismic studies and others using a digital elevation model.

The large Algerian earthquakes (267 A.D.-2017)

“…Important results have been also obtained recently in the seismic hazard evaluation (Hamdache, 1998;Aoudia et al, 2000). However, the completeness of the catalog still remains an urgent task to know more about the seismogenic zones.…”

Site-specific Seismic Hazard Estimation in the Main Seismogenic Zones of North Algeria

“…This study is an attempt to determine the site-speci®c seismic hazard parameters for the six main cities situated respectively in the six seismogenic zones in north Algeria as proposed by HAMDACHE (1998a).…”

“…Recently, several attempts were made in this area (HAMDACHE, 1998a;AOUDIA et al, 2000). All of them were based on a published seismotectonic map for northern Algeria.…”

“…The earthquake epicentral distribution (Fig. 2) and the focal mechanism distribution have been used to delineate the six seismogenic zones (HAMDACHE, 1998a). The catalogue of each identi®ed seismogenic zone was obtained using the algorithm by GODKIN and PULLI (1980).…”

“…The aim of the present work is therefore to apply the seismic hazard assessment procedure developed by SELLEVOLL (1989, 1992) and GRAHAM (1998, 1999), to each of the six seismogenic zones of north Algeria (HAMDACHE, 1998a) shown in Figure 1.…”