Automatic picking and probabilistic location for earthquake assessment in the Lesser Antilles subduction zone (1972–2012)

Abstract

Instrumental catalogues of earthquakes in the subduction zone of the Lesser Antilles are produced by local observatories and the International Seismological Centre. But none of these catalogues merge all arrival times of the first regional phases available; in addition, they have a magnitude of completeness relatively high for the entire Lesser Antilles area. As part of the Antilles Seismological Data Centre project, we produced a unified catalogue of known earthquakes from 1972 to 2012, with optimal constraints on the hypocentre locations. We re-evaluated the hypocentres with the method used in local observatories and a probabilistic method improving the distributions of arrival time residuals. We developed a simple method to select the preferred hypocentre independently of the localization algorithm, and we offer a complete catalogue including 46,703 earthquakes. Compared to other existing catalogues, we provide additional arrival times for 24,528 earthquakes. Our results highlight the variabilities of the magnitude of completeness and of the seismicity suggesting how the future analysis could infer the mechanisms of heterogeneous seismic coupling and intermediate-depth triggering.

Keywords

• Automatic phase arrival time picking
• Lesser Antilles
• Earthquakes
• Magnitude of completeness
• Absolute hypocentre location
• First phase arrival time
• Automatic phase arrival time picking