3‐D tomographic imaging of the geologic structure in the Salton Sea Geothermal Field

A three‐dimensional tomographic reconstruction of the Salton Sea Geothermal Field is presented. This reconstruction is developed from data gathered in the course of one year between 15 September 1987 and 30 September 1988 using a microearthquake network. This geothermal field is important not only due to understanding potential energy sources but also because it is the result of a tectonic spreading zone bounded between two transverse fault systems: The San Andres system to the North and the Brawley fracture zone (BFZ) to the South. Here magma has penetrated into the crust to a depth of at least 8 km. This magmatic source is responsible for the microearthquakes generated along the BFZ as well as providing the thermal source for the geothermal activity. Using techniques for both blind source estimation as well as blind deconvolution, a travel time tomographic algorithm is applied to these data. The objective is to characterize the subterranean geological structure and estimate the fracturing that supports ...