The United States Geological Survey (USGS) has been studying the water
resources in the vicinity of Fort Huachuca, Arizona. As a part of this study, they
contracted an Airborne Electromagnetic (AEM) survey of the region, which was flown in
1997. During the spring semester of 2002, the University of Arizona Geophysics Field
Camp class conducted Transient Electromagnetic (TEM) surveys at five locations near
AEM flight lines in order to provide an independent test of the resistivity structure.
We used 100 X 100 m transmitting loops. A central induction loop array was
employed where the transient decay voltage after transmitter turn off was recorded in the
center of the transmitter loop. The TEM data were inverted using a smooth modeling
program from Zonge Engineering. The resulting apparent resistivity cross sections, in
general, showed a resisitivity structure that was similar to the AEM cross sections down
to the depth of the investigation of the TEM survey (approximately 200 m). The surface
layers (zero to 50 meters) showed high resistivity (30 to 300 ohm-m) and deeper layers
showed lower resistivities (10- 30 ohm meters).
We also recorded low-induction number (LIN) EM surveys over a sink hole
feature in this area. There was a pronounced conductivity high coincident with the
sinkhole. Background conductivity readings were typically 10-15 mS/m and over the
sinkhole feature the conductivity readings were typically 20-25 mS/m.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/624619 |
| Date | 04 May 2002 |
| Creators | Call, Christopher J., Gleason, Arianna E., Kaunda, Rennie B., Meneill, Michael J., Mkandawire, Emmanuel, Palmer, Joe D., Portney, Barrie S., Sternberg, Ben K., Tembo, Jones, Wagner, Shanda L. |
| Contributors | University of Arizona |
| Publisher | LASI Laboratory for Advanced Surface Imaging, The University of Arizona (Tucson, AZ) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | Book |
| Rights | Copyright © Arizona Board of Regents |
| Relation | LASI-02-1, http://www.lasi.arizona.edu/ |
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