HR: 1340h
AN: S23B-0236    [Abstracts]
TI: Seismic Patterns of the Guerrero-Oaxaca, Mexico Region and its Relationship to the Continental Margin Structure
AU: * yamamoto, j
EM: yamas@ollin.igeofcu.unam.mx
AF: Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico, D.F., 04511 Mexico
AU: Gonzalez, T
EM: tglez@geofisica.unam.mx
AF: Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico, D.F., 04511 Mexico
AU: jimenez, z
EM: zenon@ollin.igeofcu.unam.mx
AF: Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico, D.F., 04511 Mexico
AU: quintanar, l
EM: luisq@ollin.igeofcu.unam.mx
AF: Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico, D.F., 04511 Mexico
AB: The purpose of this article is to make aware seismic evidences that suggest a possible segmentation of the continental margin at the Guerrero-Oaxaca, Mexico region. The analysis of the aftershocks of relevant earthquakes and a survey of microseismicity using a portable seismographs network permit to infer the characteristics of the seismic patterns of the Acapulco-Ometepec segment of the Middle America subduction region. Two different seismic regimes are apparent, one in the Acapulco-Copala area and another in the Ometepec-Pinotepa area. In the Acapulco-Copala area the seismicity is disperse and broader it starts at the trench up to 80 km inland. Seismicity in the Ometepec-Pinotepa area on the other hand, is narrower and concentrates near the coast. The seismic zones are separated by narrow bands of low seismic activity nearly perpendicular to the coast and trench axis. These low activity strips are interpreted as corresponding to disruptions of the continental margin. This result is important to understand the mechanics of the major earthquakes that frequently occur in this region.
DE: 7205 Continental crust (1219)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7240 Subduction zones (1207, 1219, 1240)
DE: 8104 Continental margins: convergent
DE: 8107 Continental neotectonics (8002)
SC: Seismology [S]
MN: Fall Meeting 2005