Geothermal resources are characterized by a very low electrical
resistivity of the reservoir formations. The application of electrical
methods in the reconnaissance type exploration for such resources is
discussed. It is concluded that the magneto-telluric method is very
well suited for this purpose.
In 1971 and 1972 a reconnaissance type magneto-telluric field
program was carried out in southern and eastern Oregon by the
Geophysics Group at Oregon State University. In order to reduce the
field effort, the magnetic data were obtained from a fixed base station
at Corvallis. Only the electrical field components were measured at
the various field stations. Ten stations were occupied in the Klamath
Falls area, six in central and eastern Oregon and one in the Willamette
Valley.
Impedance data were obtained in the .025 to 0.05 Hz frequency
band of the Pc 3 micropulsations. The data were analysed on the basis
of an individual event method. Only magnetic-telluric events with a
good correlation are taken into account.
The resulting apparent resistivities display some correlation
with known geothermal manifestations in the region. The lowest
resistivities of the order of 10 ohm-meters were recorded in
the Klamath Falls region and at a station near Vale in eastern Oregon.
As common in magneto-telluric work, the data display a considerable
variability, irregular scattering and anisotropy.
The results are encouraging in that they appear to indicate that
the magneto-telluric method is a useful reconnaissance method in the
regional exploration for geothermal resources. / Graduation date: 1974
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28656 |
| Date | 24 April 1974 |
| Creators | Tang, Rex Wai-yuen |
| Contributors | Bodvarsson, Gunnar |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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