CDSA: A New Seismological Data Center for the French Lesser Antilles

Abstract

The Lesser Antilles, in the eastern Caribbean, is prone to a large seismic hazard due to the subduction of the Atlantic lithosphere beneath the Caribbean plate, with a slow convergence rate of 2 cm/yr (Demets et al. 2000; Mann et al. 2002). The largest historical earthquake in the region, in 1843 between Guadeloupe and Antigua, had a magnitude estimate of 7.5 to 8 (Bernard and Lambert 1988), but historical seismicity covers too short a period of time (less than three and one-half centuries) to estimate the recurrence time of strong events or their plausible maximum magnitude. The latest destructive earthquake, Les Saintes in Guadeloupe in 2004, had a magnitude 6.3 (Institut de Physique du Globe de Paris 2004; Bertil et al. 2004). To better understand the regional geodynamics and assess the related seismic hazard, we must improve our knowledge and our understanding of the area's present seismicity. Since the 1950s, several regional research institutes have monitored local seismicity. The Institut de Physique du Globe de Paris (IPGP) and Bureau de Recherches Geologiques et Minieres (BRGM) have set up various seismological and accelerometric arrays to monitor the French islands of Guadeloupe and Martinique. As a consequence, several large datasets with very different formats and time spans exist, scattered among several sites. Providing a more integrated database for the seismicity of the Lesser Antilles arc was the primary motivation for creating the French Antilles Seismological Data Base (Centre de Donnees Sismologiques des Antilles, CDSA). The aim of this paper is to introduce the newly created CDSA and to illustrate its capacity for improving our knowledge of the region's seismicity. In the first part of this study, we present the various arrays, waveform databases, and seismicity catalogs used by the CDSA. In the second part, we present and discuss new …