Un modelo sísmico preliminar lateralmente heterogéneo del campo geotérmico de Cerro Prieto Baja California Norte

Abstract

About 125 selected events recorded by the CICESE network at the Cerro Prieto area were used to study the underlying structure in terms of P-wave velocity. The events were chosen according to their position with respect to three nearly aligned stations and used to draw travel time curves for different parts of the profile. It is supposed that the structure under this profile is representative of the region of geothermal production. This analysis establishes a preliminary model of the structure, to be used for more detaUed investigations and, at the same time, tests a simple ray tracing method for heterogeneous two-dimensional media. Since seismic events are natural phenomena, the results are highly dependent on the accuracy of previously determined locations. In sorne cases, the reported errors are great, in others the recordings are dubious or incomplete, so we considered the trend shown by hypocenters to cluster at specific depths. We hope to begin an event-relocation model-reparameterization cycle as soon as new data are avaUable. Here we advance our conclusion that controlled source experiments with broader seismic arrays would help to clearly defme boundaries. These in tum could be correlated to real geological structures, demonstrating the possible connection between transform fault systems such as San Jacinto-Elsinore, Imperial-Cerro Prieto. Similarly, faults associate¡.l wj.th fluid conduction and other phenomena of geotectonic interest could be identified.