Las zonas sísmicas de Costa Rica y alrededores

Abstract

Seismic and tectonic data were usad in arder to find out the different zones in which the Costa Rica and its surrounding could be dívided. On that purpose, a reeompiled catalog of earthquakes from dífferent sources has been aeeamplished and several events were relocated based an macroseismic data. The obtained seismic zones are the result of combined space-time entena, seismic energy release, rup cure zone, seismic gaps, focal mechanism solutions and the local and regional tec tonic. The region of the Pacific margen, has been divide in six zones, toward the SE, three of them: Chiriquí, Osa and Quepos, separated for N-S fractures. As infered fault system with NE direction, separates the Quepas from Nicoya zona. Northwest of Nicoya, are located the Papagayo and Masachapa zone, with no evidenee of fracture or faults between them nor in cheir bourders, but a parcial decoupling and downbending of the subducted piare probably applied te them. In the magmatic are, were found different zones: Managua, Arenal, Valle Central and General Coto Brus, and in the back are basin, the litoral Atlantico zone. The large seismic energy release in the Pacific margen is in correspandence with the Gulf area of both Nicoya and Osa, and for the magmatic are of Costa Rica, belongs ca che Arenal zone.