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Person

Steven M Cahan

Cartographer

Email: scahan@usgs.gov
Office Phone: 703-648-6435
Fax: 703-648-6419
ORCID: 0000-0002-4776-3668

Location
12201 Sunrise Valley Drive
Reston , VA 20192-0002
US
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The storage assessment unit (SAU) is the fundamental unit used in the National Assessment of Geologic Carbon Dioxide Storage Resources project for the assessment of geologic CO2 storage resources. The SAU is shown here as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the assessment interval. Individual SAUs are defined on the basis of common geologic and hydrologic characteristics. The resource that is assessed is the mass of CO2 that can be stored in the technically accessible pore volume of a storage formation. The technically accessible storage resource is one that may be available using present-day geological and engineering knowledge and technology for CO2 injection...
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Open pit uranium mining in Atascosa, Karnes, and Live Oak Counties in the Texas gulf coast region was active during the second half of the 20th century. Understanding the history of these mining operations is important for proper management and restoration. Although some mines have extensive records documenting the locations and extents of mining pits and mine waste-rock piles, and provide descriptions of reclamation activities, abandoned mines with little to no such documentation are present on the landscape. A multiple lines of evidence approach using lidar derivatives and multispectral remote sensing temporal analysis (Stengel, 2022) was developed to (1) identify uranium mine waste-rock, wastewater, and land...
Open pit uranium mining in Atascosa, Karnes, and Live Oak Counties in the Texas gulf coast region was active during the second half of the 20th century. Understanding the history of these mining operations is important for proper management and restoration. Although some mines have extensive records documenting the locations and extents of mining pits and mine waste-rock piles, and provide descriptions of reclamation activities, abandoned mines with little to no such documentation are present on the landscape. A multiple lines of evidence approach using lidar derivatives and multispectral remote sensing temporal analysis (cite paper here) was developed to (1) identify uranium mine waste-rock, wastewater, and land...
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We developed a methodology to estimate maximum brine injection rates in subsurface formations across wide geographic areas using inverse modeling-based optimization techniques. We first defined geographic areas where groundwater was too saline to meet the standard for drinking water and where sufficient confining units existed above and below the injection layers. We then assumed concurrent brine injection into a system of wells on a consistent 25 km x 25 km spacing across the entire modeled area. Taking advantage of symmetry, we represented each 25 km x 25 km injection area as a 12.5 km-long one-dimensional radial model, divided into 100 logarithmically-sized grid blocks. A single layer of grid blocks was used...
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Open pit uranium mining in Atascosa, Karnes, and Live Oak Counties in the Texas gulf coast region was active during the second half of the 20th century. Understanding the history of these mining operations is important for proper management and restoration. Although some mines have extensive records documenting the locations and extents of mining pits and mine waste-rock piles, and provide descriptions of reclamation activities, abandoned mines with little to no such documentation are present on the landscape. A multiple lines of evidence approach using lidar derivatives and multispectral remote sensing temporal analysis (Stengel, 2022) was developed to (1) identify uranium mine waste-rock, wastewater, and land...
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