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Full-Text Articles in Physical Sciences and Mathematics
Integrated Borehole, Radar, And Seismic Velocity Analysis Reveals Dynamic Spatial Variations Within A Firn Aquifer In Southeast Greenland, S. F. Killingbeck, N. C. Schmerr, L. N. Montgomery, A. D. Booth, P. W. Livermore, J. Guandique, O. L. Miller, S. Burdick, R. R. Forster, L. S. Koenig, A. Legchenko, S. R. M. Ligtenberg, C. Miège, D. K. Solomon, L. J. West
Integrated Borehole, Radar, And Seismic Velocity Analysis Reveals Dynamic Spatial Variations Within A Firn Aquifer In Southeast Greenland, S. F. Killingbeck, N. C. Schmerr, L. N. Montgomery, A. D. Booth, P. W. Livermore, J. Guandique, O. L. Miller, S. Burdick, R. R. Forster, L. S. Koenig, A. Legchenko, S. R. M. Ligtenberg, C. Miège, D. K. Solomon, L. J. West
Environmental Science and Geology Faculty Research Publications
Perennial water storage in firn aquifers has been observed within the lower percolation zone of the southeast Greenland ice sheet. Spatially distributed seismic and radar observations, made ~50 km upstream of the Helheim Glacier terminus, reveal spatial variations of seismic velocity within a firn aquifer. From 1.65 to 1.8 km elevation, shear-wave velocity (Vs) is 1,290 ± 180 m/s in the unsaturated firn, decreasing below the water table (~15 m depth) to 1,130 ± 250 m/s. Below 1.65 km elevation, Vs in the saturated firn is 1,270 ± 220 m/s. The compressional-to-shear velocity ratio decreases in the downstream saturated zone, …
Direct P-Wave Anisotropy Measurements At Homestake Mine: Implications For Wave Propagation In Continental Crust, James Atterholt, Sarah J. Brownlee, Gary L. Pavlis
Direct P-Wave Anisotropy Measurements At Homestake Mine: Implications For Wave Propagation In Continental Crust, James Atterholt, Sarah J. Brownlee, Gary L. Pavlis
Environmental Science and Geology Faculty Research Publications
We measured anisotropic seismic properties of schists of the Homestake Formation located at a depth of 1478 m in the Sanford Underground Research Facility (SURF) in the Black Hills of South Dakota, USA. We deployed a 24-element linear array of three-component geophones in an area in the Homestake Mine called 19-ledge. An airless jackhammer source was used to shoot two profiles: (1) a walkaway survey to appraise any distance dependence and (2) a fan shot profile to measure variations with azimuth. Slowness estimates from the fan shot profile show a statistically significant deviation with azimuth with the expected 180° variation …
A Framework For Aquatic Invasive Species Surveillance Site Selection And Prioritization In The Us Waters Of The Laurentian Great Lakes, Andrew J. Tucker, W. Lindsay Chadderton, Gust Annis, Alisha D. Davidson, Joel Hoffman, Jon Bossenbroek, Stephen Hensler, Michael Hoff, Erika Jensen, Donna R. Kashian, Sarah Lesage, Timothy Strakosh
A Framework For Aquatic Invasive Species Surveillance Site Selection And Prioritization In The Us Waters Of The Laurentian Great Lakes, Andrew J. Tucker, W. Lindsay Chadderton, Gust Annis, Alisha D. Davidson, Joel Hoffman, Jon Bossenbroek, Stephen Hensler, Michael Hoff, Erika Jensen, Donna R. Kashian, Sarah Lesage, Timothy Strakosh
Environmental Science and Geology Faculty Research Publications
Risk-based prioritization for early detection monitoring is of utmost importance to prevent and mitigate invasive species impacts and is especially needed for large ecosystems where management resources are not sufficient to survey all locations susceptible to invasion. In this paper we describe a spatially-explicit and quantitative approach for identifying the highest risk sites for aquatic invasive species (AIS) introduction into the United States’ waters of the Laurentian Great Lakes, a vast inland sea with a surface area of 246,049 square km and a shoreline length of 16,431 km. We compiled data from geospatial metrics available across all of the US …