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1974 geothermal field tests at the Niland Reservoir in the Imperial Valley of California

Description: The phases of the 1974 geothermal field tests at the Niland Reservoir in the Imperial Valley of California are documented. The following tests are included: separator, steam scrubber, steam turbine, heat exchanger, packed heat exchanger, corrosion, chemical cleaning, and control and instrumentation. (MHR)
Date: January 1, 1974
Partner: UNT Libraries Government Documents Department

Hydrothermal System and Seismic Activity of Hakone Volcano

Description: The structure of the Hakone hydrothermal system and geochemistry of thermal waters are described. The subsurface temperature map and the zonal distribution of thermal waters strongly suggest that thermal energy of the Hakone system is essentially supplied by dense volcanic steam rich in sodium chloride coming up through the volcanic conduit, from which subsurface streams of sodium chloride waters are derived. The seismic activity of Hakone mostly takes place at relatively shallow depths in the central part of the caldera. The chemical and physical properties of the dense steam are examined assuming that the phase transformation of water to steam is the major cause for volcanic earthquakes. The Cl-SO{sub 4} chemistry permits estimation of sodium chloride content of 0.5 to 1% in original dense steam responsible for sodium chloride waters. Thanks to the work of Sourirajan and Kennedy (1962) temperature pressure condition of volcanic dense steam at depths of 1 to 2 km below sea-level is estimated to be about 385 C and 230 bars, dissolving 0.5 to 1% of sodium chloride in steam. Below the depth of 4 km, earthquakes seldom occur, the hydrothermal system is saturated with solid sodium chloride, resulting in lowered vapor pressure. This implies that the permeation of meteoric water to the volcanic steam system mostly takes place at a depth less than 4 km. The analogy of hot eyes (centers of geothermal fields) and cold eyelids (surroundings of low temperature area) is emphasized for better understanding of hydrothermal systems.
Date: January 1, 1974
Creator: Oki, Y. & Hirano, T.
Partner: UNT Libraries Government Documents Department

Seismic Noise Surveys in Geothermal Areas

Description: Some evidence suggests that high seismic noise levels are associated with geothermal systems. Clacy (1968) and Whiteford (1970) found that large seismic amplitudes, in the frequency range of 1-10 Hz, occur in the vicinity of known geothermal areas in the North Island of New Zealand. In Imperial Valley, California, Goforth, Douze and Sorrells (1972) found a seismic noise anomaly that nearly coincides with a thermal anomaly near the southeastern shore of Salton Sea, and Douze and Sorrells (1972) found high noise levels over the Mesa thermal anomaly. The US Geological Survey (USGS) made seismic noise measurements in Imperial Valley and Long Valley, California, and Yellowstone National Park, Wyoming, to evaluate whether seismic noise can be used as a prospecting tool in geothermal exploration. One Hz seismometers with slow-speed tape-recording systems were used. About 50-80 stations were occupied with average spacing of 0.5-1.5 km, and each station was operated for at least 48 hours. The results described are based on average noise amplitudes computed using playbacks of several sections of data recorded at night when wind-generated noise was absent.
Date: January 1, 1974
Creator: Iyer, H. M.
Partner: UNT Libraries Government Documents Department