Permissive tracts for shoreline placer titanium deposits in Mauritania (phase V, deliverable 84): Chapter P1 in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)
Georges Beaudoin, John D. Horton
2012, Open-File Report 2013-1280-P1
In 1996, at the request of the Government of the Islamic Republic of Mauritania, a team of U.S. Geological Survey (USGS) scientists produced a strategic plan for the acquisition, improvement and modernization of multidisciplinary sets of data to support the growth of the Mauritanian minerals sector and to highlight the...
Mineral potential tracts for orogenic, Carlin-like, and epithermal gold deposits in the Islamic Republic of Mauritania, (phase V, deliverable 68): Chapter H1 in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)
Richard J. Goldfarb, Erin E. Marsh, John D. Horton
2012, Open-File Report 2013-1280-H1
In 1996, at the request of the Government of the Islamic Republic of Mauritania, a team of U.S. Geological Survey (USGS) scientists produced a strategic plan for the acquisition, improvement and modernization of multidisciplinary sets of data to support the growth of the Mauritanian minerals sector and to highlight the...
Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water
Anthony M. Pagano, George M. Durner, Kristin S. Simac, G.S. York, Steven C. Amstrup
2012, Canadian Journal of Zoology (90) 663-676
Polar bears (Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a...
Lidar base specification
Hans Karl Heidemann
2012, Techniques and Methods 11-B4
In late 2009, a $14.3 million allocation from the American Recovery and Reinvestment Act (ARRA) for new light detection and ranging (lidar) elevation data acquisition prompted the U.S. Geological Survey (USGS) National Geospatial Program (NGP) to develop a common minimum specification for all lidar data acquired for The National Map....
Near-bed turbulence and sediment flux measurements in tidal channels
S.A. Wright, D.R. Whealdon-Haught
2012, Conference Paper, Proceedings of the Hydraulic Measurement and Experimental Methods Conference, Snowbird, Utah, August 12-15, 2012
Understanding the hydrodynamics and sediment transport dynamics in tidal channels is important for studies of estuary geomorphology, sediment supply to tidal wetlands, aquatic ecology and fish habitat, and dredging and navigation. Hydrodynamic and sediment transport data are essential for calibration and testing of numerical models that may be used to...
Genesis of an oak-fire science consortium
K.W. Grabner, M. C. Stambaugh, R.P. Guyette, D. C. Dey, G.D. Willson
D. C. Dey, M. C. Stambaugh, S.L. Clark, C. J. Schweitzer, editor(s)
2012, Conference Paper, Proceedings of the 4th Fire in Eastern Oak Forest Conference, Gen. Tech. Rep. NRS-P-102
With respect to fire management and practices, one of the most overlooked regions lies in the middle of the country. In this region there is a critical need for both recognition of fire’s importance and sharing of fire information and expertise. Recently we proposed and were awarded funding by the...
Stratigraphic architecture of bedrock reference section, Victoria Crater, Meridiani Planum, Mars
Lauren A. Edgar, John P. Grotzinger, Alex G. Hayes, David M. Rubin, Steve W. Squyres, James F. Bell, Kenneth E. Herkenhoff
2012, Book chapter, Sedimentary geology of Mars
The Mars Exploration Rover Opportunity has investigated bedrock outcrops exposed in several craters at Meridiani Planum, Mars, in an effort to better understand the role of surface processes in its geologic history. Opportunity has recently completed its observations of Victoria crater, which is 750 m in diameter and exposes...
Testing the effect of water in crevasses on a physically based calving model
S. Cook, T. Zwinger, I.C. Rutt, Shad O’Neel, T. Murray
2012, Annals of Glaciology (53) 90-96
A new implementation of a calving model, using the finite-element code Elmer, is presented and used to investigate the effects of surface water within crevasses on calving rate. For this work, we use a two-dimensional flowline model of Columbia Glacier, Alaska. Using the glacier's 1993 geometry as a starting point,...
Complexity of human and ecosystem interactions in an agricultural landscape
Richard H. Coupe, Jeannie R. B. Barlow, Paul D. Capel
2012, Environmental Development (4) 88-104
The complexity of human interaction in the commercial agricultural landscape and the resulting impacts on the ecosystem services of water quality and quantity is largely ignored by the current agricultural paradigm that maximizes crop production over other ecosystem services. Three examples at different spatial scales (local, regional, and global) are...
Spread dynamics of perennial pepperweed (Lepidium latifolium) in two seasonal wetland areas
Mark J. Renz, Scott J. Steinmaus, David S. Gilmer, Joseph M. DiTomaso
2012, Invasive Plant Science and Management (5) 57-68
Perennial pepperweed is an invasive plant that is expanding rapidly in several plant communities in the western United States. In California, perennial pepperweed has aggressively invaded seasonal wetlands, resulting in degradation of habitat quality. We evaluated the rate and dynamics of population spread, assessed the effect of disturbance on spread,...
An atlas of Mars sedimentary rocks as seen by HiRISE
Ross Beyer, Kathryn M. Stack, Jennifer L. Griffes, Ralph E. Milliken, Kenneth E. Herkenhoff, Shane Byrne, John W. Holt, John P. Grotzinger
John P. Grotzinger, Ralph E. Milliken, editor(s)
2012, Book chapter, Sedimentary geology of Mars
Images of distant and unknown places have long stimulated the imaginations of both explorers and scientists. The atlas of photographs collected during the Hayden (1872)expedition to the Yellowstone region was essential to its successful advocacy and selection in 1872 as America’s first national park. Photographer William...
Physical Climate Forces
S.J. Williams, D. Atkinson, A. R. Byrd, H. Eicken, T. M. Hall, Thomas G. Huntington, Y. Kim, T.R. Knutson, J.P. Kossin, M. Lilly, J. M. Marra, J Obeysekera, A. Parris, J. Ratcliff, T. Ravens, D. Resio, P. Ruggiero, E. Robert Thieler, James G. Titus, T.V. Wamsley
2012, Book chapter, Coastal Impacts, Adaptation and Vulnerability: A Technical Input to the 2012 National Climate Assessment. Cooperative Report to the 2013 National Climate Assessment
Key FindingsThe coasts of the U.S. are home to many large urban centers and important infrastructure such seaports, airports, transportation routes, oil import and refining facilities, power plants, and military bases. All are vulnerable to varying degrees to impacts of global warming such as sea-level rise, storms, and flooding. High Confidence.Physical observations collected...
A catalog of Louisiana's nesting seabird colonies
William R. Fontenot, Steve W. Cardiff, Richard A. DeMay, Donna L. Dittmann, Stephen B. Hartley, Clinton W. Jeske, Nicole Lorenz, Thomas C. Michot, Robert Dan Purrington, Michael A. Seymour, William G. Vermillion
2012, Barataria-Terrebonne National Estuary Program Report 34
Summarizing his colonial nesting waterbird survey experiences along the northern coast of the Gulf of Mexico in a paper presented to the Colonial Waterbird Group of the Waterbird Society (Portnoy 1978), bird biologist John W. Portnoy stated, “This huge concentration of nesting waterbirds, restricted almost entirely to the wetlands and...
Developing a national stream morphology data exchange: needs, challenges, and opportunities
Mathias J. Collins, John R. Gray, Marie C. Peppler, Faith A. Fitzpatrick, Joseph P. Schubauer-Berigan
2012, Eos, Transactions, American Geophysical Union (93) 195
Stream morphology data, primarily consisting of channel and foodplain geometry and bed material size measurements, historically have had a wide range of applications and uses including culvert/ bridge design, rainfall- runoff modeling, food inundation mapping (e.g., U.S. Federal Emergency Management Agency food insurance studies), climate change studies, channel stability/sediment source...
The 2011 Virginia earthquake: what are scientists learning?
J. Wright Horton Jr., Robert A. Williams
2012, Eos, Transactions, American Geophysical Union (93) 317-318
Nearly 1 year ago, on 23 August, tens of millions of people in the eastern United States and southeastern Canada were startled in the middle of their workday (1:51 P.M. local time) by the sudden onset of moderate to strong ground shaking from a rare magnitude (M) 5.8 earthquake in...
Social.Water - A crowdsourcing tool for environmental data acquisition
Michael N. Fienen, Christopher Lowry
2012, Computers & Geosciences (49) 164-169
Remote telemetry has a long history of use for collection of environmental measurements. With the rise of mobile phones and SMS text-messaging capacity, many members of the general pubic carry communications equipment in their pockets at all times. Enabling the general public to provide environmental data through text messages has...
Varying sediment sources (Hudson Strait, Cumberland Sound, Baffin Bay) to the NW Labrador Sea slope between and during Heinrich events 0 to 4
John T. Andrews, D.C. Barber, A. E. Jennings, D. D. Eberl, B. Maclean, M.E. Kirby, J.S. Stoner
2012, Journal of Quaternary Science (27) 475-484
Core HU97048-007PC was recovered from the continental Labrador Sea slope at a water depth of 945 m, 250 km seaward from the mouth of Cumberland Sound, and 400 km north of Hudson Strait. Cumberland Sound is a structural trough partly floored by Cretaceous mudstones and Paleozoic carbonates. The record extends from ∼10 to...
Formation of replicating saponite from a gel in the presence of oxalate: implications for the formation of clay minerals in carbonaceous chondrites and the origin of life
Dirk Schumann, Hyman Hartman, Dennis D. Eberl, S. Kelly Sears, Reinhard Hesse, Hojatollah Vali
2012, Astrobiology (12) 549-561
The potential role of clay minerals in the abiotic origin of life has been the subject of ongoing debate for the past several decades. At issue are the clay minerals found in a class of meteorites known as carbonaceous chondrites. These clay minerals are the product of aqueous alteration of...
Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska
Cynthia Dusel-Bacon, Nora K. Foley, John E. Slack, Alan E. Koenig, Robert L. Oscarson
2012, Economic Geology (107) 1403-1432
Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t)...
Distribution of arsenic, selenium, and other trace elements in high pyrite Appalachian coals: evidence for multiple episodes of pyrite formation
S. F. Diehl, M. B. Goldhaber, A.E. Koenig, H.A. Lowers, L.F. Ruppert
2012, International Journal of Coal Geology (94) 238-249
Pennsylvanian coals in the Appalachian Basin host pyrite that is locally enriched in potentially toxic trace elements such as As, Se, Hg, Pb, and Ni. A comparison of pyrite-rich coals from northwestern Alabama, eastern Kentucky, and West Virginia reveals differences in concentrations and mode of occurrence of trace elements in...
Holocene seasonal variability inferred from multiple proxy records from Crevice Lake, Yellowstone National Park, USA
Cathy Whitlock, Walter E. Dean, Sherilyn C. Fritz, Lora R. Stevens, Jeffery R. Stone, Mitchell J. Power, Joseph R. Rosenbaum, Kenneth L. Pierce, Brandi B. Bracht-Flyr
2012, Palaeogeography, Palaeoclimatology, Palaeoecology (331-332) 90-103
A 9400-yr-old record from Crevice Lake, a semi-closed alkaline lake in northern Yellowstone National Park, was analyzed for pollen, charcoal, geochemistry, mineralogy, diatoms, and stable isotopes to develop a nuanced understanding of Holocene environmental history in a region of northern Rocky Mountains that receives both summer and winter precipitation. The...
Distribution of potentially bioavailable natural organic carbon in aquifer sediments at a chloroethene-contaminated site
L.K. Thomas, M.A. Widdowson, F. H. Chapelle, J.T. Novak, J.E. Boncal, C. A. Lebron
2012, Journal of Environmental Engineering (139) 54-60
The distribution of natural organic carbon was investigated at a chloroethene-contaminated site where complete reductive dechlorination of tetrachloroethene (PCE) to vinyl chloride and ethene was observed. In this study, operationally defined potentially bioavailable organic carbon (PBOC) was measured in surficial aquifer sediment samples collected at varying depths and locations in...
Potentially bioavailable natural organic carbon and hydrolyzable amino acids in aquifer sediments
Lashun K. Thomas, Mark A. Widdowson, John T. Novak, Francis H. Chapelle, Ronald Benner, Karl Kaiser
2012, Ground Water Monitoring and Remediation (32) 92-95
This study evaluated the relationship between concentrations of operationally defined potentially bioavailable organic -carbon (PBOC) and hydrolyzable amino acids (HAAs) in sediments collected from a diverse range of chloroethene--contaminated sites. Concentrations of PBOC and HAA were measured using aquifer sediment samples collected at six selected study sites. Average concentrations of...
The first direct evidence of pre-columbian sources of palygorskite for Maya Blue
Dean E. Arnold, Bruce F. Bohor, Hector Neff, Gary M. Feinman, Patrick Ryan Williams, Laure Dussubieux, Ronald Bishop
2012, Journal of Archaeological Science (39) 2252-2260
Maya Blue, a nano-structured clay–organic complex of palygorskite and indigo, was used predominantly before the Spanish Conquest. It has fascinated chemists, material scientists, archaeologists and art historians for decades because it is resistant to the effect of acids, alkalis, and other reagents, and its rich color has persisted for centuries...
Structure and mechanism of diet specialisation: testing models of individual variation in resource use with sea otters
M. Tim Tinker, Paulo R. Guimaraes Jr., Mark Novak, Flavia Maria Darcie Marquitti, James L. Bodkin, Michelle Staedler, Gena B. Bentall, James A. Estes
2012, Ecology Letters (15) 475-483
Studies of consumer-resource interactions suggest that individual diet specialisation is empirically widespread and theoretically important to the organisation and dynamics of populations and communities. We used weighted networks to analyze the resource use by sea otters, testing three alternative models for how individual diet specialisation may arise. As expected, individual...
