Seismicity patterns in the State of Guerrero, Mexico, 1974-2013: Its implication for the Guerrero Seismic Gap
Abstract
The Guerrero Seismic Gap (GSG), has not been ruptured by a large earthquake (> 7.5), since 1911. The GSG is located along the Pacific Coast in central Guerrero State. This region, situated 300 km away from Mexico City, has been the site of important earthquakes, that have caused intensive damage at the capital of Mexico. A close look at the epicentral distribution in Guerrero State, between 1974 and 2013, shows that 3,496 earthquakes with magnitudes greater than 4, are located principally between the Middle America Trench and the coast, and a smaller number of events are located along a section that parallels the coast at about 80-110 Km inland. The hypocentral locations, mainly after 1995, when the digital seismic network started operating, show a good correlation with the generally proposed shallow dipping geometry of the subducting plate. Other observations in the epicentral distribution, are linear groups aligned with bathymetric features, and seismic clusters. Some of these regions can be seen as coalescence and fragmentation zones. There have been three slow-slip seismic events at the Guerrero region, every four years, between 1998 and 2010, and no particular epicentral distribution has been observed during these periods. Even with this large number of epicenters analyzed, is possible to distinguish the GSG. We analyze temporal variations of the epicentral and hypocentral distribution, and found that the seismic void for the GSG, suggest elliptical areas with width and length axis of 50-80 Km for the minimum area and 70-130 Km, for the maximum area. If this regions represent the possible rupture area of the expected earthquake, they will correspond to magnitudes of 7.6 to 8.2. The latest is the hypothetical working magnitude for the Mexican Federal Government. Although, with this information it is not possible to evaluate the state of the GSG, it is important to stablish the behavior of the seismicity before the ocurrance of an expected major earthquake.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.S22A..01V
- Keywords:
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- 7223 SEISMOLOGY Earthquake interaction;
- forecasting;
- and prediction;
- 7230 SEISMOLOGY Seismicity and tectonics