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Three-dimensional seismic image of a geothermal reservoir: The Geysers, California

January 1, 1996

Three-dimensional seismic travel-time tomography of The Geysers geothermal area, in the coast ranges of northern California, shows a strong (-9%) anomaly in VP/VS, the ratio of the compressional and shear wave speeds, that is not evident in Vp alone and corresponds closely to the most intensively exploited part of the geothermal reservoir. This anomaly probably indicates low pore pressure and relatively dry conditions, caused partly by boiling of pore water as steam is extracted. Steam pressure decreases over the last decade have probably caused seismologically measurable changes in wave speeds. Tomographic measurement of Vp/Vs is a promising technique both for identifying geothermal resources and for monitoring them during exploitation.

Citation Information

Publication Year 1996
Title Three-dimensional seismic image of a geothermal reservoir: The Geysers, California
DOI
Authors B.R. Julian, A. Ross, G.R. Foulger, J.R. Evans
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Series Number
Index ID 70018180
Record Source USGS Publications Warehouse
USGS Organization Volcano Hazards Program