UC Riverside

We present updated time-series and velocities based on survey (episodic) Global Positioning System (GPS) measurements across the geothermal field at The Geysers, California. These surveys show that a slowing of the rapid rate of subsidence and contraction seen across The Geysers has occurred since the start of the Southeast Geysers Effluent Pipeline (SEGEP) in October 1997 and the Santa Rosa Geysers Recharge Pipeline (SRGRP) in September 2003, most significantly in areas close to high volume injector wells, although subsidence is still occurring. We also introduce the first continuous GPS sites in The Geysers, which were installed in December 2012 and January 2013. These continuous sites are intended to capture and monitor transient deformation associated with Calpine's Enhanced Geothermal Systems demonstration projects.