Teleseismic-Seismic Monitoring At Valles Caldera - Sulphur Springs Geothermal Area (Steck, Et Al., 1998)
Exploration Activity: Teleseismic-Seismic Monitoring At Valles Caldera - Sulphur Springs Geothermal Area (Steck, Et Al., 1998)
|Exploration Activity Details|
|Location||Valles Caldera - Sulphur Springs Geothermal Area|
|Exploration Technique||Teleseismic-Seismic Monitoring|
|Activity Date||1993 - 1994|
This study reports on results of the Jemez Tomography Experiment (JTEX), a multidisciplinary effort to understand the structure of the Jemez volcanic field below the Valles Caldera. The experiment incorporates active and passive seismology, geology, gravity, and electromagnetic studies that allow for deep 3-D modeling of the subsurface beneath the caldera.
Active and passive teleseismic surveys were performed over the the summers of 1993 and 1994, and were designed to build successively on one another and on a 2-D teleseismic survey performed in 1987 by Roberts et al. (1991). Data from the first active teleseismic survey are reported by Nishimura et al. (1997). The 1993 array consisted of two intersecting NW-SE and SW-NE lines, with two small-aperture arrays built out from from one or more stations on the NW-SE line, each using three additional stations. The deployment consisted of a total of 22 short-period Mark Products L-4 and L-22 stations. The 1994 array consisted of 50 three-component Ref-Tek DAS stations including a Streckheisen STS-2, 30 Guralp 3-ESPs, 2 Guralp 40Ts, 10 Teledyne Geotech S-13s, and 8 Mark Products L-4s. Sensors were deployed along the same 1993 survey lines, lengthening the lines and forming a 2-D network of stations covering the caldera. The deployment also included a broadband eight-station array with a 3 km aperture north of Valle Grande and several stations around the Toledo embayment. A total of 4872 P wave arrival times were combined to produce a detailed 3-D inversion model of the crust and upper mantle structure in a 42x42x40 km volume (116 picks from the 1987 survey, 1169 picks from the 1993 survey, and 3703 picks from the 1994 survey).
- Lee K. Steck, Clifford H. Thurber, Michael C. Fehler, William J. Lutter, Peter M. Roberts, W. Scott Baldridge, Darrik G. Stafford, Robert Sessions (1998) Crust and Upper Mantle P Wave Velocity Structure Beneath Valles Caldera, New Mexico- Results from the Jemez Teleseismic Tomography Experiment