Regional and local networks of horizontal control, Cerro Prieto geothermal area, Mexico
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Abstract
The Cerro Prieto geothermal area in the Mexicali Valley 30 km southeast of Mexicali, Baja California, is probably deforming due to (1) the extraction of large volumes of steam and hot water, and (2) active tectonism. Two networks of precise horizontal control were established in Mexicali Valley by the U.S. Geological Survey in 1977-78 to measure both types of movement as they occur. These networks consisted of (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from survey stations on an existing U.S. Geological Survey crustal-strain network north of the international border, and (2) a local net tied to stations in the regional net and encompassing the area of present and planned geothermal production. Survey lines in this net were selected to span areas of probable ground-surface movements in and around the geothermal area.
Electronic distance measuring (EDM) instruments, operating with a modulated laser beam, were used to measure the distances between stations in both networks. The regional net was run using a highly precise long-range EDM instrument, helicopters for transportation of men and equipment to inaccessible stations on mountain peaks, and a fixed wing airplane flying along the line of sight. Precision of measurements with this complex long-range system approached 0.2 parts per million of line length. The local net was measured with medium range EDM instrument requiring minimal ancillary equipment. Precision of measurements with this less complex system approached 3 parts per million for the shorter line lengths.
The detection and analysis of ground-surface movements resulting from tectonic strains or induced by geothermal fluid withdrawal is dependent on subsequent resurveys of these networks.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Regional and local networks of horizontal control, Cerro Prieto geothermal area, Mexico |
| Series title | Open-File Report |
| Series number | 78-929 |
| DOI | 10.3133/ofr78929 |
| Year Published | 1978 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Description | 6 p. |
| Country | Mexico |
| State | Baja California |
| Other Geospatial | Cerro Prieto geothermal area |
| Google Analytic Metrics | Metrics page |