GEOTHERMAL TECHNOLOGIES LEGACY COLLECTION - Bibliographic Citation


Bibliographic Citation


Full Text:
L E G A C Y
application/pdf
3 Mb

View Full Text Access Individual Pages  -   Search, view and/or download individual pages
Title: Controlled-source electromagnetic survey at Soda Lakes geothermal area, Nevada
Creator/Author: Stark, M. ; Wilt, M. ; Haught, J.R. ; Goldstein, N.
Publication Date:1980 Jul 01
OSTI Identifier:OSTI 5111455
Report Number(s):LBL-11221
DOE Contract Number:W-7405-ENG-48
Document Type:Technical Report
Specific Type:
Coverage:
Resource Relation:Other Information: PBD: 1 Jul 1980
Other Number(s):
Research Org:California Univ., Berkeley, CA (US); Lawrence Berkeley Lab. (US)
Sponsoring Org:Not Available (US)
Subject:15 GEOTHERMAL ENERGY; AMPLITUDES; BASEMENTS; ELECTROMAGNETIC SURVEYS; GEOTHERMAL FIELDS; MAGNETIC FIELDS; POLARIZATION; PROSPECTING; THICKNESS; VELOCITY; NEVADA; GEOLOGIC MODELS; GEOTHERMAL EXPLORATION; DATA; GEOLOGY; HYDROLOGY; KGRA; ELECTRICAL SURVEYS; EXPLORATION; GEOPHYSICAL SURVEYS; INFORMATION; NORTH AMERICA; USA
Keywords:GEOTHERMAL LEGACY
Description/Abstract:The EM-60 system, a large-moment frequency-domain electromagnetic loop prospecting system, was operated in the Soda Lakes geothermal area, Nevada. Thirteen stations were occupied at distances ranging from 0.5-3.0 km from two transmitter sites. These yielded four sounding curves--the normalized amplitudes and phases of the vertical and radial magnetic fields as a function of frequency--at each station. In addition, two polarization ellipse parameters, ellipticity and tilt angle, were calculated at each frequency. The data were interpreted by means of a least-squares inversion procedure which fits a layered resistivity model to the data. A three-layer structure is indicated, with a near-surface 20 ohm-m layer of 100-400 m thickness, a middle 2 ohm-m layer of approximately 1 km thickness, and a basement of greater than 10 ohm-m. The models indicate a northwesterly structural strike; the top and middle layers seem to thicken from northeast to southwest. The results agree quite well with previous results of dipole-dipole and magnetotelluric (MT) surveys. The EM-60 survey provided greater depth penetration (1 to 1.5 km) than dipole-dipole, but MT far surpassed both in its depth of exploration. One advantage of EM in this area is its ease and speed of operation. Another advantage, its relative insensitivity to lateral inhomogeneities, is not as pronounced here as it would be in areas of more complex geology.
Publisher:
Country of Publication:US
Language:English
Size/Format:Medium: ED; Size: 98 pages
Rights:
Availability:NTIS, PC A05/MF A01.; OSTI as DE05111455
System Entry Date:2013 Apr 15
 View Non-Empty Fields Only

Top

Some links on this page may take you to non-federal websites. Their policies may differ from this site.