Radiated seismic energy of aftershocks of the 20 March 2012 earthquake, Mw7.5, Ometepec-Pinotepa Nacional, Mexico.

Abstract:

Radiated seismic energy is a valuable parameter in assessing the size and source characteristics of an earthquake. We study aftershocks of the 20 March 2012 earthquake (Mw7.5) in Ometepec-Pinotepa Nacional,located in the subduction zone of the Pacific coast of Mexico, with the purpose of examining the distribution of the scaled seismic energy (Es) with seismic moment (Mo), Es/Mo, over the main event’s rupture area. We estimate Es from regional velocity and acceleration records. For some, larger, aftershocks we also estimate Es from teleseismic data. Preliminary energy estimations suggest that aftershocks closer to the trench have a smaller Es/Mo ratio. In contrast, Es/Mo is larger for events closer to the coast (near the epicenter of the mainshock).