2-D Inversion of Seismic Attenuation Observations in Coso Hot Springs, KGRA

Abstract

Seismograms from over sixty teleseismic events recorded by a sixteen element vertical component telemetered seismograph array installed by the U.S. Geological Survey in the Coso Hot Springs, Known Geothermal Resource Area (KGRA) have been analyzed to determine the lateral variation of seismic attenuation using the reduced spectral ratio technique. Seismograms of events from the SE and NW azimuths observed at a five station linear array have been used to infer a 2-D Q-1 model across the center of the geothermal system. A constrained generalized linear inversion algorithm was used to infer the Q-1 model. The model contains 15 cells with boundaries at depth of 5, 20, and 33 km and Q variation from 32 to 890. The zone of high attenuation dips from surface between Coso Hot Springs and Airport Lake toward the northwest beneath Devil's Kitchen.