| Title | Seismic Wave Attenuation Anomalies in the East Mesa Geothermal Field, Imperial Valley, California: Preliminary Results |
|---|---|
| Authors | Combs, Jim; Jarzabek, Dave |
| Year | 1978 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Exploration; USA; California; Imperial; East Mesa; Tectonics; P Wave; Earthquakes |
| Abstract | Seismic wave attenuation anomalies are known to be associated with geothermal areas. Data have been analyzed from calibration blasts detonated within the East Mesa Geothermal Field from six events of the Brawley earthquake swarm of January 1975, recorded at portable seismic stations deployed in the vicinity of the geothermal field. Alignment of two or more stations of the array with particular epicenters facilities the removal of source characteristics. Spectral analyses of these calibration shots and earthquake generated seismic waves have shown anomalous attenuation of the high frequency P waves along certain ray paths. The results suggest that the source of the heat anomaly responsible for the East Mesa Geothermal Field is located at depths greater than two kilometers and has a lateral extent of several kilometers. |