The silent earthquake of 2002 in the Guerrero seismic gap, Mexico (Mw=7.6): Inversion of slip on the plate interface and some implications

We invert GPS position data to map fhe slip on the plate interface during an aseismic, slow~slip event, which occurred in 2002 in the Guerrero seismic gap of the M~xican subduction zone, lasted for -4 months, and was detected by 7 continuous GPS receivers located over an area of -550x250 km2. Our be...

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Detalles Bibliográficos
Autores: Iglesias, A., Singh, S. K., Lowry, A. R., Kostoglodov, V., Larson, K. M., Franco-Sanchez, S. I.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2004
País:México
Institución:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repositorio:Geofísica Internacional
Idioma:español
inglés
OAI Identifier:oai:revistagi.geofisica.unam.mx:article/953
Acceso en línea:http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/953
Access Level:acceso abierto
Palabra clave:Sismo lento
Brecha sisimica de Guerrero
GPS
Slow earthquake
Guerrero seismic gap
Descripción
Sumario:We invert GPS position data to map fhe slip on the plate interface during an aseismic, slow~slip event, which occurred in 2002 in the Guerrero seismic gap of the M~xican subduction zone, lasted for -4 months, and was detected by 7 continuous GPS receivers located over an area of -550x250 km2. Our best model, under physically reasonable constraints, shows that the slow slip occurred on the transition zone at a distancejrange oflOO to 170 km from the trench. The average slip was about 22.5 em (Mo-2.97 xlOZ7 dyne-em, Mw=7.6). This model implies an increased shear stress at the bottom of the locked, seismogenic part of the interface which lies updip from the transition zone, and, hence, an enhanced seismic hazard. The results from other similar subduction zones also favor this model. However, we cannot rule out an alternative model that requires slow slip to invade the seismogenic zone as well. A definitive answer to this critical issue would require more GPS stations and long-term monitoring.