Focal mechanism and rupture process of the 2012 M _w 7.0 Santa Isabel, Mexico earthquake inverted by teleseismic data

Abstract

The point source parameters of the April 12, 2012 M _w 7.0 Santa Isabel, Mexico, earthquake indicated by teleseismic P and SH waveforms obtained by a means of traditional cut and paste (CAP) method show that the best double-couple solution of this event is: 37°/127°, 90°/81° and −9°/−180° for strike, dip and rake, respectively. Its centroid depth is 13 km. Global teleseismic waveform data exhibit that the rupture of the earthquake initiated at a focal depth of 13 km and propagated southeastward with a relatively slow rupture velocity (about 1.8 km/s on average). The maximum slip occurred at 30 km southeast of the hypocenter, with the peak slip of 3.57 m and total seismic moment of whole fault up to 3.98×10¹⁹ N·m. These observations provide some insight into properties, co- or post-seismic deformation and coulomb stress changes of future earthquake in this area.

Keywords

Mexico Earthquake / rupture velocity / focal mechanism / slip history

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