Research drilling at the Salton Sea Geothermal Field, California: The Shallow Thermal Gradient Project



During November and December 1985, a series of shallow (80-m or 250-ft.) holes were drilled in the southern Salton Sea. Temperatures in these holes will be logged for at least 3 months after drilling to establish equilibrium temperatures. The intent is to close the thermal gradient contours of the field and thus define the width of the transition zone between the locations exhibiting high thermal gradients and those exhibiting regional thermal gradients in the area north of the volcanic domes. These observations will allow competing models [e.g., Riney et al., 1977; Rex, 1983; Kasameyer et al., 1984] for the circulation of the hydrothermal system to be tested and will provide a more accurate assessment of the size of the geothermal resource.