Seismological investigations at The Geysers geothermal field

Stress and Fracture Orientation in the Northwest Geysers Geothermal Field

A dataset comprised of 3946 well-located and wellconstrained earthquake focal plane mechanisms recorded in the Northwest Geysers geothermal field during the period of Jan 2005 – May 2012 was used to determine stress orientations and relative magnitudes at fine scale. The stress inversions were organized into gridblocks of varying size using a three-dimensional oct-tree gridding algorithm in whi...

Three-dimensional Compressional- and Shear-wave Seismic Velocity Models for the Southeast Geysers Geothermal Field, California

Three-dimensional compressionaland shear-wave velocity (“Vp” and “Vs,” respectively) structure is obtained for the SE Geysers geothermal area from microearthquake arrival-time data. The results indicate a region of high Vp and high Vs in the northwest portion of the area studied, and a low value of VpNs at depths corresponding to the upper part of the steam reservoir. The Vp and Vs anomalies ar...

Adsorption Characteristics of Rocks from Vapgr-dominated Geothermal Reservoir at the Geysers, Ca

Mathematical Problems of Seismological Monitoring of Geothermal Areas

Most of geothermal areas are located in seismically active regions. Because of an intensive tectonic regime, discontinuities of their lithosphere play the role of channels for powerful metallogenic heat and mass transfer processes, especially for intrusion of ultra-basic magmas with Fe, Mn etc. into the crust. Proceeding from the presence of substantial low resistivity structures in seismic lit...

The Stress State of the Northwest Geysers, California Geothermal Field, and Implications for Fault-Controlled Fluid Flow

A dataset comprised of well-constrained focal mechanisms for 6147 earthquakes recorded in the northwest Geysers geothermal field during the period of 2005–2012 was utilized to conduct a detailed stress study within and below the geothermal reservoir. The high-quality focal mechanisms were organized into grid blocks of varying size using a 3D octree gridding algorithm in which discretization was...