Electrical resistivity survey of the Salton Sea geothermal field Imperial Valley, Calfornia. [Schlumberger, equatorial, and dipole-dipole soundings]

Technical Report · Sat May 01 04:00:00 EDT 1976

OSTI ID:7143455

Meidav, T; West, R; Katzenstein, A; Rotstein, Y

An extensive electrical resistivity survey was conducted in the Salton Sea Geothermal Field, Imperial Valley, California. Very high energizing power (upward of 200 amperes) was employed to determine the extremely low resistivities (less than 0.5 ohmmeters) which were expected, to depths of 3 to 6 km. A combination of Schlumberger, equatorial, and dipole-dipole sounding techniques was employed and ultra-low commutation periods were used to avoid skin depth effects. Some depth soundings were extended into the sea by means of the equatorial sounding approach. The findings of the resistivity survey are combined with a previously reported marine seismic survey of the Salton Sea. They indicate that a very complex structural-hydrogeological pattern exists in the area. Integration of all existing data suggests that the Salton Sea geothermal field is an expression of active crustal spreading presently taking place along the southern shore of the Sea. The resistivity survey revealed the existence of six significant faults in the area. These are named here as the Wister, Calipatria, Red Hill, Brawley, Fondo and Westmorland Faults. The discovered faults act as either aquicludes or aquitards, probably with varying degrees of sealing effectiveness along their length. Comparison of existing isothermal maps, structural maps and the iso-resistivity data leads to the conclusion that sharp salinity gradients must exist in the area. Radical changes in vertical and lateral resistivity distributions suggest that a complex stratigraphic-temperature-salinity pattern exists in the area.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7143455
• Report Number(s): UCRL-13690(Vols.1-2)
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150301* -- Geothermal Exploration & Exploration Technology-- Geophysical Techniques & Surveys
CALIFORNIA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRICAL SURVEYS
EXPLORATION
GEOLOGIC FAULTS
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
GEOTHERMAL EXPLORATION
GEOTHERMAL FIELDS
IMPERIAL VALLEY
NORTH AMERICA
PHYSICAL PROPERTIES
SALTON SEA GEOTHERMAL FIELD
TECTONICS
USA
WESTERN REGION