Source process and stress change associated with the 11 January, 1997 (Mw=7.1) Michoacán, Mexico, inslab earthquake
We study the source characteristics and the associated coseismic stress change of the January 11, 1997 Michoacán earth-quake, based on teleseismic, regional and near-source recordings. This event was located just beneath the ruptured zone of the 1985 Michoacán thrust event. From the inversion of tel...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | México |
| Recursos: | UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO |
| Repositorio: | Geofísica Internacional |
| Idioma: | español inglés |
| OAI Identifier: | oai:revistagi.geofisica.unam.mx:article/203 |
| Acesso em linha: | http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/203 |
| Access Level: | acceso abierto |
| Palavra-chave: | Inversión cinemática de la fuente esfuerzos de Coulomb interacción de sismos Kinematic source inversion Coulomb failure stress earthquake interaction |
| Resumo: | We study the source characteristics and the associated coseismic stress change of the January 11, 1997 Michoacán earth-quake, based on teleseismic, regional and near-source recordings. This event was located just beneath the ruptured zone of the 1985 Michoacán thrust event. From the inversion of teleseismic recordings, we obtain a nearly-vertical faulting at 35 km depth, a total source duration of 15 sec, a moment magnitude of Mw=7.1, and a mean rupture velocity of 2.8 km/sec. An analysis of teleseismic and local seismograms shows that the rupture had a strong directivity to the southeast, with a rather complex source-time function with two main subevents and a total duration of 13 sec. The dislocation distribution obtained from 2D kinematic linear inversion, using both local strong motion and broad-band teleseismic data, shows a complex rupture pattern with the main seismic moment release occurring in the southwest portion of the fault. A comparison between the coseismic Coulomb failure stress change during the main shock, and the location and mechanism of the aftershocks, suggests that post-event seismicity may have been triggered by the stress changes due to the main event. |
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