July 6, 2015
Onshore Industrial Wind Turbine Locations for the United States through July 2013
By Jay Diffendorfer (GECSC), Roger Compton, Louisa Kramer (GECSC), Zach Ancona (GECSC), and Donna Norton. USGS Data Series 817.
Unlike oil and gas wells, there has been a lack of publicly available information about wind turbines within the United States. This motivated a study by the USGS to map industrial-scale onshore wind turbine locations and record corresponding facility information and turbine technical specifications. The resulting database presented in this report has more than 47,000 wind turbine records that have been collected, digitized, locationally verified, and internally quality controlled.
July 1, 2015
Geologic map of the Orchard 7.5' quadrangle, Morgan County, Colorado
By Margaret Berry (GECSC), Janet Slate, Paul Hanson, and Ted Brandt (GECSC). USGS Scientific Investigations Map 3331.
The Orchard 7.5' quadrangle is located along the South Platte River corridor on the semi-arid plains of eastern Colorado, west of Ft. Morgan. The mapped area contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated through environmental changes from the Pleistocene to the present. Along with the map and georeferenced map PDFs, this publication includes downloadable GIS files.
June 10, 2015
Late Quaternary sea-level history and the antiquity of mammoths (Mammuthus exilis and Mammuthus columbi), Channel Islands National Park, California, USA
By Dan Muhs (GECSC), Kathleen Simmons (GECSC), Lindsey Groves, Jack McGeehin, Randy Schumann (GECSC), and Larry Agenbroad. Published in Quaternary Research.
Mammoth fossils are sometimes found in Channel Islands National Park, and most date to the last glacial period (Marine Isotope Stage [MIS] 2, about 25,000 to 12,000 years ago). Recently, however, a tusk was found in the lowest marine terrace of Santa Rosa Island (MIS 5.1, about 80,000 years ago), which dates it to a time of relatively high sea level. Mammoths mostly likely swam to the islands, and the favorable times to do so (other than MIS 2) would have been during glacial periods MIS 6 (~150,000 years ago) or MIS 8 (~250,000 years ago) which were times of low sea level. The date of the MIS 5.1 fossil challenges the hypothesis that climate change, vegetation change, and decreased land area from sea-level rise were the causes of mammoth extinction at the Pleistocene/Holocene boundary on the Channel Islands, because pre-MIS 2 mammoth populations would have experienced similar or even more dramatic changes at the MIS 6/5.5 transition.