Earth Tidal Analysis At East Mesa Geothermal Area (1984)

GEOTHERMAL ENERGY

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Exploration Activity: Earth Tidal Analysis At East Mesa Geothermal Area (1984)

Exploration Activity Details
Location	East Mesa Geothermal Area
Exploration Technique	Earth Tidal Analysis
Activity Date	1984
Usefulness	useful
DOE-funding	Unknown

Exploration Basis

Determine porosity of the reservoir

Notes

The response of a confined, areally infinite aquifer to external loads imposed by earth tides is examined. Because the gravitational influence of celestial objects occurs over large areas of the earth, the confined aquifer is assumed to respond in an undrained fashion. Since undrained response is controlled by water compressibility, earth tide response can be directly used only to evaluate porous medium compressibility if porosity is known. In the present work, change in external stress is estimated from dilatation by assuming a reasonable value for bulk modulus. Earth tide response of geothermal aquifers were analyzed, and the ratio of S₃ to porosity was estimated. Comparison of these estimates with independent pumping tests show reasonable agreement.

References

• Narasimhan, T.N.; Kanehiro, B.Y.; Witherspoon, P.A.   (10 March 1984) Interpretation of earth tide response of three deep, confined aquifers