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Polar bears (Ursus maritimus) require the relative warmth and stability afforded by snow dens for successful reproduction. Pregnant bears must travel from foraging habitats on the sea ice to land in autumn to establish winter dens. Data of sea ice extent and composition from satellite-acquired passive microwave (PMW) imagery show a reduction in summer sea ice extent throughout the Arctic from 1979-2006. Additionally, General Circulation Models (GCM) predict that Arctic sea ice extent will continue to diminish throughout the 21st century. Greater energetic demands will be placed on pregnant polar bears in the future if they travel greater distances from summer forage habitats to traditional denning habitats on land....
Categories: Publication; Types: Citation; Tags: Administrative Report
This dataset tabulates input data for simulations of undiscovered copper resources in porphyry copper deposits that were done using the EMINERS computer program (Duval, J.S., 2012, Version 3.0 of EMINERS—Economic Mineral Resource Simulator: U.S. Geological Survey Open-File Report 2004–1344, as part of a global mineral resource assessment. The input data consist of information for 163 permissive tracts for porphyry copper deposits in 7 world regions. A GIS of the permissive tracts and selected data are available in Dicken, C.L., Dunlap, Pamela, Parks, H.L., Hammarstrom, J.M., and Zientek, M.L., 2016, Spatial database for a global assessment of undiscovered copper resources: U.S....
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