Geothermal exploration using imaging spectrometer data over Fish Lake Valley, Nevada

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• 作者：Elizabeth F. Littlefield ; Wendy M. Calvin
• 关键词：Fish Lake Valley ; Nevada ; Geothermal ; Remote sensing ; Imaging spectrometer
• 刊名：Remote Sensing of Environment
• 出版年：January, 2014
• 年：2014
• 卷：140
• 期：Complete
• 页码：509-518
• 全文大小：2508 K

文摘

The U.S. currently leads the world in installed geothermal capacity with power plants in eight states, and exploration for new electrical-grade geothermal systems is ongoing. Geothermal systems at depth may be identified at the surface by hot springs and fumaroles or by minerals produced by thermal fluids (hydrothermal alteration and hot spring deposits). Northern Fish Lake Valley, Nevada hosts two previously known geothermal fields. This study expanded prospects and identified new areas for future exploration within the valley. We demonstrated the potential for using remote sensing data to evaluate regions that are not well explored. We used visible, near, and shortwave infrared (0.4-2.5 渭m) remote sensing data to map surficial mineralogy. Data were collected by three airborne imaging spectrometer instruments, AVIRIS, HyMap, and ProSpecTIR, each over different parts of Fish Lake Valley. Minerals were identified using diagnostic spectral features. We verified remote sensing results in the field using a portable spectrometer to confirm agreement between field and remote spectra.

The discovery of additional geothermal resources in Fish Lake Valley may provide the necessary added incentive to build costly transmission lines to this remote location. We used remote sensing data to delineate four new targets for future geothermal exploration in northern Fish Lake Valley. Two new areas of sinter and travertine deposits were identified northwest of the playa, likely deposited around fault-controlled hot springs during the Pleistocene when the water table was higher. Previously undocumented Miocene crystalline travertine was identified within the Emigrant Hills. Argillic alteration was mapped within ranges, where thermal fluids were likely discharged from faults to alter rhyolite tuff. Here we explain our data processing techniques which include a novel decorrelation stretch designed for geothermal prospecting, and discuss how remote sensing results guided our interpretation of the region's geothermal systems.