Geothermal Development and Changes in Surficial Features: Examples from the Western United States

Abstract

Changes in surficial thermal features and land-surface elevations can accompany development of geothermal reservoirs. Such changes have been documented to varying extents at geothermal fields in the Western United States, including Long Valley caldera, Coso Hot Springs, and Amadee Hot Springs in California, and Steamboat Springs, Beowawe, Dixie Valley, and Brady Hot Springs in Nevada. The best-documented cases are for the Casa Diablo area in Long Valley caldera, California and for Steamboat Springs, Nevada where hydrologic monitoring programs have delineated some combination of declines in thermal-water discharge, increases in fumarolic steam discharge, and subsidence. At other areas noted above, similar types of changes have occurred but existing monitoring programs do not permit the same level of analysis of cause-and-effect relationships between such surficial changes and contributing factors.