Neo-deterministic seismic hazard assessment in North Africa

• Published in: Journal of seismology 2014-04, Vol.18 (2), p.301-318
• Main Authors: Mourabit, T., Abou Elenean, K. M., Ayadi, A., Benouar, D., Ben Suleman, A., Bezzeghoud, M., Cheddadi, A., Chourak, M., ElGabry, M. N., Harbi, A., Hfaiedh, M., Hussein, H. M., Kacem, J., Ksentini, A., Jabour, N., Magrin, A., Maouche, S., Meghraoui, M., Ousadou, F., Panza, G. F., Peresan, A., Romdhane, N., Vaccari, F., Zuccolo, E.
• Format: Article
• Language: English
• Subjects: Algorithms; Assessments; Earth and Environmental Science; Earth Sciences; Earthquakes; Economics; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hazards; Hydrogeology; Original Article; Seismic activity; Seismic hazard; Seismic phenomena; Seismology; Structural Geology; Structural models; Wave propagation; Zonation
• ISSN: 1383-4649; 1573-157X
• DOI: 10.1007/s10950-013-9375-2

North Africa is one of the most earthquake-prone areas of the Mediterranean. Many devastating earthquakes, some of them tsunami-triggering, inflicted heavy loss of life and considerable economic damage to the region. In order to mitigate the destructive impact of the earthquakes, the regional seismic hazard in North Africa is assessed using the neo-deterministic, multi-scenario methodology (NDSHA) based on the computation of synthetic seismograms, using the modal summation technique, at a regular grid of 0.2 × 0.2°. This is the first study aimed at producing NDSHA maps of North Africa including five countries: Morocco, Algeria, Tunisia, Libya, and Egypt. The key input data for the NDSHA algorithm are earthquake sources, seismotectonic zonation, and structural models. In the preparation of the input data, it has been really important to go beyond the national borders and to adopt a coherent strategy all over the area. Thanks to the collaborative efforts of the teams involved, it has been possible to properly merge the earthquake catalogues available for each country to define with homogeneous criteria the seismogenic zones, the characteristic focal mechanism associated with each of them, and the structural models used to model wave propagation from the sources to the sites. As a result, reliable seismic hazard maps are produced in terms of maximum displacement ( D max ), maximum velocity ( V max ), and design ground acceleration.