PRELIMINARY GEOMORPHOLOGIC AND PALEOSEISMIC INVESTIGATIONS ALONG THE AGUA FRIA FAULT IN THE LOS AZUFRES VOLCANIC EDIFICE: AN ATTEMPT TOWARDS SEISMIC HAZARD ASSESSMENT IN CENTRAL MEXICO

The Morelia–Acambay Fault System (MAFS) is a < 260 km long fault system bounded by Acambay Graben to the east and the Cuitzeo Graben to the west. Till date, most of the paleoseismic investigations were focus on the epicentral area of known crustal earthquakes, in the Acambay and Cuitzeo grabens. However there are several undocumented crustal faults between these grabens that are long enough to generate large magnitude earthquakes. In this study, we used a multidisciplinary approach (Geomorphology and Paleoseismology) to characterize the earthquake history of the Agua Fria Fault, one of the largest faults of the MAFS central segment. The fault traces and associated landforms like triangular facets, ponding and scarps were mapped using high resolution satellite imageries and topographic data. The geomorphological data indicate that the fault scarp is at least 13 km long striking E-W and is height varies from few meters to hundreds of meters. Three trenches were excavated at three different sites along the Agua Fria fault. Preliminary results indicate that various earthquakes were produced by this fault during Pleistocene.