Estudio del mecanismo de reajuste litostático posterior al evento de Oaxaca (ms = 7.8) del 29 de noviembre de 1978

Abstract

The aftershock seismic activity (ML>3.0) related to the Oaxaca earthquake of November 29, 1978 was anal y sed for the period from December 1 to 12, 1978. Focal mechanism solutions for 9 main aftershocks (ML>4.0) and composite mechanisms for 13 low magnitude aftershocks associated to the principal event show normal faulting with a trend striking parallel to the mesoamerican Trench. These results suggest a tensional adjustment which causes downstepped block faulting parallel to the Benioff zone in the area. This mechanism may be common to the main earthquakes related to the subduction in the central Oaxacan coastal region.