An improved P-wave velocity reference model for Costa Rica

Abstract

We derive a P-wave 1D-velocity model for Costa Rica that may serve for routine high-precision earthquake location and as initial reference model for 3D seismic tomography. The velocity inversions are performed using 822 well-locatable events together with 14774 P-wave observations obtained by merging routine travel time data from 10 335 earthquakes in the period 1984 to 1997 collected by the Universidad Nacional de Costa Rica (OVSICORI), and 3510 earthquakes in the period 1992 to 1998 collected by the Red Sismológica Nacional (RSN) in Costa Rica. Special care is taken during the merging process to reduce the number of errors in the data and, in particular, to update, correct, and complete the station parameter list. Consistency and quality are given priority over completeness of the resulting data set. The final data set for the period 1984 to 1998 in Costa Rica consists of 11 848 local events with 13 2331 P-wave and 86018 S-wave observations.