A. Dib¹ , M. Bezzeghoud² , M. Hamoudi¹ , C. Dorbath³ , L. Dorbath³

¹University of Science and Technology Houari Boumediene
²Universidade de Évora, Escola de Ciências e Tecnologia (ECT)
³Université de Strasbourg, Ecole et Observatoire des Sciences de la Terre

Abstract:

The seismicity of the Portuguese territory increases in intensity from north to south, with a spatial distribution concentrated in the south and its adjacent Atlantic margins. The present seismological study, focused around Algarve region, it was carried out through a cooperation project between the Universities of Evora (Portugal), Lisbon (Portugal), Strasbourg (France) and the IPMA (Lisbon, Portugal). To locate the seismic events and find the local velocity structure of epicentral area, the P and S arrival timesat 38 stations are used(Geostar stations, telemetered network, U. Lisbon and IPMA stations). The data used in this study were obtained during the Algarve campaign, which worked, from January/2006 to July/2007. The preliminary estimate of origin times and hypocentral coordinates are determined by the Hypoinverse program. Linearized inversion procedure was applied to comprise the following two steps: 1) finding the velocity model using Velest and 2) simultaneous relocation of hypocenters and determination of local velocity structure. This work is expected to produce a more detailed knowledge of the crust structure over the region of Algarve, being able to identify seismogenic zones, potentially generators of significant seismic events andalso the identification of zones of active faults.