Generation of isoseismal maps for Mexico using velocity and acceleration data

Abstract

Acceleration and velocity data of large earthquakes recorded by the Mexican National Broadband Seismological Network were used to generate isoseismal maps for Mexico. The seismic data consist of 99 events recorded at 27 seismic stations located in the southern and northern regions of Mexico from 2004 to 2009. The magnitude (Mw) of these events ranged from 4.1 to 7.1. Peak ground velocity values (PGV) and peak ground accelerations (PGA) were estimated, and velocity-derived peak ground accelerations (PGAv) were calculated. No important differences between PGAv and PGA values were found; thus, both parameters were used in the isoseismal determination. The generated synthetic isoseismal maps were compared with those from an existing catalog for large earthquakes in Mexico. Using empiric relations between PGA and MMI (modified Mercalli intensity) and PGV and MMI, the obtained simulated intensity maps showed similar behavior to those reported in the catalog. The results indicate that the PGAv values can be used to determine intensities when acceleration records (PGA) are unavailable.