Relocation and waveform modeling of the 1924 Orotina, Costa Rica, earthquake
Fecha
2009-08
Tipo
artículo original
Autores
Fernández Arce, Mario Enrique
Doser, Diane
Título de la revista
ISSN de la revista
Título del volumen
Editor
Resumen
We have determined the location and focal mechanism for the 1924 Orotina earthquake using two different relocation algorithms developed for the analysis of historic earthquakes and forward waveform modeling of teleseismic body waves. Our relocation results suggest that the 1924 earthquake occurred ~50 km southeast of Orotina near the Pacific coast. The heavy damage reported in the Orotina region, coupled with a low population density to the southeast, had led previous researchers to believe that the earthquake occurred near Orotina, possibly on the Tarcoles or Bijagual faults. Our waveform modeling results indicate rupture on a thrust fault at a depth (25±5 km) near the plate interface with Mw 6.4–6.7. These are inconsistent with slip on any mapped surface faults located near Orotina and with the mechanism of the nearby 2004 Mw 6.4 Damas earthquake that indicates transtensional deformation in the upper crust. This suggests that the 1924 event may be one of a sequence of events (1924, 1990, 1999) generated by subduction of the central Costa Rica seamount belt.
Descripción
Artículo científico--Universidad de Costa Rica, Vicerrectoría de Acción Social, Extensión Docente.2004. Para mayor información puede escribir a accion.social@ucr.ac.cr
Palabras clave
Sismología, Geología estructural, Sismo, Orotina