Faulting process and coseismic stress change during the 30 January, 1973, Colima, Mexico interplate earthquake (Mw=7.6)

A large thrust earthquake (Mw=7.6) occurred on January 30, 1973, on the plate interface between the subducting Cocosplate and the continental North America plate, near the triple junction between the North America, Cocos and Rivera Plates.This event might be related to two sequences of subsequent la...

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Detalles Bibliográficos
Autores: Luis Quintanar, Miguel A. Santoyo, Takeshi Mikumo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2006
País:México
Institución:Universidad Nacional Autónoma de México
Repositorio:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:56845302
Acceso en línea:https://www.redalyc.org/articulo.oa?id=56845302
Access Level:acceso abierto
Palabra clave:Ciencias de la Tierra
Coseismic stress change
Descripción
Sumario:A large thrust earthquake (Mw=7.6) occurred on January 30, 1973, on the plate interface between the subducting Cocosplate and the continental North America plate, near the triple junction between the North America, Cocos and Rivera Plates.This event might be related to two sequences of subsequent large earthquakes that occurred around this region. Althoughseveral authors have analyzed the focal mechanism and depth of this earthquake, we analyzed its source characteristics andperformed a linear kinematic waveform inversion for the slip distribution over the fault plane. We find a shallow thrust mechanism(St=285°, Dip=16°, Ra=85°) consistent with the tectonic environment, with a depth of 16 km and a total moment release of2.98x1027 dyn-cm. The results show a slip distribution with two main patches, with a maximum dislocation of 199 cm and 173cm respectively. We calculated the coseismic stress change on and around the fault plane. This earthquake ruptured two mainasperities, one downdip and southwest and the other updip and northwest of the hypocenter, with stress change of –31 and -40bars respectively The surrounding zone of stress increase could have influenced the subsequent seismicity to a distance of up to120 km from the hypocenter.