Late Quaternary sedimentological and climate changes at Lake Bosumtwi Ghana: new constraints from laminae analysis and radiocarbon age modeling
Timothy M. Shanahan, J. Warren Beck, Jonathan T. Overpeck, Nicholas P. McKay, Jeffrey S. Pigati, John A. Peck, Christopher A. Scholz, Clifford W. Heil Jr., John W. King
2012, Palaeogeography, Palaeoclimatology, Palaeoecology (361-362) 49-60
The Lake Bosumtwi sediment record represents one of the longest and highest-resolution terrestrial records of paleoclimate change available from sub-Saharan Africa. Here we report a new sediment age model framework for the last ~ 45 cal kyr of sedimentation using a combination of high-resolution radiocarbon dating, Bayesian age-depth modeling and...
Holocene dune formation at Ash Meadows National Wildlife Area, Nevada, USA
Nicholas Lancaster, Shannon Mahan
2012, Quaternary Research (78) 266-274
Small isolated dune fields in the northern Mojave Desert are important centers of biodiversity and archaeological occupation sites. Currently dunes at Ash Meadows, Nevada, are stabilized by vegetation and are experiencing erosion of their upwind margins, indicating a negative sediment budget. New OSL ages from dunes at Ash Meadows indicate...
Emerging contaminants at a closed and an operating landfill in Oklahoma
William J. Andrews, Jason R. Masoner, Isabelle M. Cozzarelli
2012, Groundwater Monitoring & Remediation (32) 120-130
Landfills are the final depositories for a wide range of solid waste from both residential and commercial sources, and therefore have the potential to produce leachate containing many organic compounds found in consumer products such as pharmaceuticals, plasticizers, disinfectants, cleaning agents, fire retardants, flavorings, and preservatives, known as emerging contaminants...
Modeling responses of large-river fish populations to global climate change through downscaling and incorporation of predictive uncertainty
Mark L. Wildhaber, Christopher K. Wikle, Christopher J. Anderson, Kristie J. Franz, Edward H. Moran, Rima Dey
Helmut Mader, Julia Kraml, editor(s)
2012, Conference Paper, 9th International Symposium on Ecohydraulics 2012 Proceedings
Climate change operates over a broad range of spatial and temporal scales. Understanding its effects on ecosystems requires multi-scale models. For understanding effects on fish populations of riverine ecosystems, climate predicted by coarse-resolution Global Climate Models must be downscaled to Regional Climate Models to watersheds to river hydrology...
Characterization of previously unidentified lunar pyroclastic deposits using Lunar Reconnaissance Orbiter Camera (LROC) data
J. Olaf Gustafson, James F. Bell, Lisa R. Gaddis, B. Ray Hawke, Thomas A. Giguere
2012, Journal of Geophysical Research E: Planets (117)
We used a Lunar Reconnaissance Orbiter Camera (LROC) global monochrome Wide-angle Camera (WAC) mosaic to conduct a survey of the Moon to search for previously unidentified pyroclastic deposits. Promising locations were examined in detail using LROC multispectral WAC mosaics, high-resolution LROC Narrow Angle Camera (NAC) images, and Clementine multispectral (ultraviolet-visible...
Assessing consumption of bioactive micro-particles by filter-feeding Asian carp
Nathan R. Jensen, Jon J. Amberg, James A. Luoma, Liza R. Walleser, Mark P. Gaikowski
2012, Journal of Aquaculture Research & Development (3)
Silver carp Hypophthalmichthys molitrix (SVC) and bighead carp H. nobilis (BHC) have impacted waters in the US since their escape. Current chemical controls for aquatic nuisance species are non-selective. Development of a bioactive micro-particle that exploits filter-feeding habits of SVC or BHC could result in a new control tool. It...
Design and development of linked data from the National Map
E. Lynn Usery, Dalia E. Varanka
2012, Semantic Web (3) 371-384
The development of linked data on the World-Wide Web provides the opportunity for the U.S. Geological Survey (USGS) to supply its extensive volumes of geospatial data, information, and knowledge in a machine interpretable form and reach users and applications that heretofore have been unavailable. To pilot a process to take...
Dryland biological soil crust cyanobacteria show unexpected decreases in abundance under long-term elevated CO2
Blaire Steven, La Verne Gallegos-Graves, Chris M. Yeager, Jayne Belnap, R. David Evans, Cheryl R. Kuske
2012, Environmental Microbiology (14) 3247-3258
Biological soil crusts (biocrusts) cover soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in biocrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested...
Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge
M.O. Cuthbert, R. Mackay, J. R. Nimmo
2012, Hydrology and Earth System Sciences (9) 8455-8492
Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is developed and tested using a range of numerical models, including a modified soil moisture balance model (SMBM) for estimating groundwater recharge in the...
Calving seismicity from iceberg-sea surface interactions
T.C. Bartholomaus, C.F. Larsen, Shad O’Neel, M.E. West
2012, Journal of Geophysical Research F: Earth Surface (117)
Iceberg calving is known to release substantial seismic energy, but little is known about the specific mechanisms that produce calving icequakes. At Yahtse Glacier, a tidewater glacier on the Gulf of Alaska, we draw upon a local network of seismometers and focus on 80 hours of concurrent, direct observation of...
Geomagnetic detection of the sectorial solar magnetic field and the historical peculiarity of minimum 23-24
Jeffrey J. Love, J. Rigler
2012, Geophysical Research Letters (39)
[1] Analysis is made of the geomagnetic-activityaaindex covering solar cycle 11 to the beginning of 24, 1868–2011. Autocorrelation shows 27.0-d recurrent geomagnetic activity that is well-known to be prominent during solar-cycle minima; some minima also exhibit a smaller amount of 13.5-d recurrence. Previous work has shown that the recent solar...
Developing spatially explicit footprints of plausible land-use scenarios in the Santa Cruz Watershed, Arizona and Sonora
Laura M. Norman, Mark Feller, Miguel L. Villarreal
2012, Landscape and Urban Planning (107) 225-235
The SLEUTH urban growth model is applied to a binational dryland watershed to envision and evaluate plausible future scenarios of land use change into the year 2050. Our objective was to create a suite of geospatial footprints portraying potential land use change that can be used to aid binational decision-makers...
Downscaling future climate projections to the watershed scale: A north San Francisco Bay estuary case study
Elisabeth Micheli, Lorraine Flint, Alan Flint, Stuart Weiss, Morgan Kennedy
2012, San Francisco Estuary and Watershed Science (10)
We modeled the hydrology of basins draining into the northern portion of the San Francisco Bay Estuary (North San Pablo Bay) using a regional water balance model (Basin Characterization Model; BCM) to estimate potential effects of climate change at the watershed scale. The BCM calculates water balance components, including runoff,...
ShakeMap Atlas 2.0: an improved suite of recent historical earthquake ShakeMaps for global hazard analyses and loss model calibration
D. Garcia, R.T. Mah, K. L. Johnson, M.G. Hearne, K. D. Marano, K.-W. Lin, D.J. Wald
2012, Conference Paper, The 15th World Conference on Earthquake Engineering: September 24-28, 2012, Lisbon, Portugal
We introduce the second version of the U.S. Geological Survey ShakeMap Atlas, which is an openly-available compilation of nearly 8,000 ShakeMaps of the most significant global earthquakes between 1973 and 2011. This revision of the Atlas includes: (1) a new version of the ShakeMap software that improves data usage and...
Conflicts between sandhill cranes and farmers in the western United States: evolving issues and solutions
Jane E. Austin
2012, Conference Paper, Cranes, Agriculture and Climate Change, May 28 - June 3, 2010, Muraviovka Park for Sustainable Land Use, Amur Region, Russia
The main conflicts between Sandhill Cranes (Grus canadensis) and farmers in western United States occur in the Rocky Mountain region during migration and wintering periods. Most crop damage by cranes occurs in mature wheat (Triticum aestivum) and barley (Hordeum vulgare), young shoots of alfalfa (Medicago sativa) and cereal grains, chilies...
Drainage network structure and hydrologic behavior of three lake-rich watersheds on the Arctic Coastal Plain, Alaska
C.D. Arp, M.S. Whitman, Benjamin M. Jones, R. Kemnitz, G. Grosse, F.E. Urban
2012, Arctic, Antarctic, and Alpine Research (44) 385-394
Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrost and snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km2 Fish...
Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico
Helen K. White, Pen-Yuan Hsing, Walter Cho, Timothy M. Shank, Erik E. Cordes, Andrea M. Quattrini, Robert K. Nelson, Richard Camilli, Amanda W.J. Demopoulos, Christopher R. German, James M. Brooks, Harry H. Roberts, William Shedd, Christopher M. Reddy, Charles R. Fisher
2012, PNAS (109) 20303-20308
To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited...
Density-dependent nest predation in waterfowl: the relative importance of nest density versus nest dispersion
Joshua T. Ackerman, Kevin M. Ringelman, J.M. Eadie
2012, Oecologia (169) 695-702
When nest predation levels are very high or very low, the absolute range of observable nest success is constrained (a floor/ceiling effect), and it may be more difficult to detect density-dependent nest predation. Density-dependent nest predation may be more detectable in years with moderate predation rates, simply because there can...
Allowable levels of take for the trade in Nearctic songbirds
Fred A. Johnson, Matthew A.H. Walters, G. Scott Boomer
2012, Ecological Applications (22) 1114-1130
The take of Nearctic songbirds for the caged-bird trade is an important cultural and economic activity in Mexico, but its sustainability has been questioned. We relied on the theta-logistic population model to explore options for setting allowable levels of take for 11 species of passerines that were subject to legal...
Nuclear and mitochondrial markers reveal evidence for genetically segregated cryptic speciation in giant Pacific octopuses from Prince William Sound, Alaska
Rebecca K. Toussaint, David Scheel, G. Kevin Sage, Sandra L. Talbot
2012, Conservation Genetics (13) 1483-1497
Multiple species of large octopus are known from the north Pacific waters around Japan, however only one large species is known in the Gulf of Alaska (the giant Pacific octopus, Enteroctopus dofleini). Current taxonomy of E. dofleini is based on geographic and morphological characteristics, although with advances in genetic technology...
A horizon scanning assessment of current and potential future threats to migratory shorebirds
William J. Sutherland, José A. Alves, Tatsuya Amano, Charlotte H. Chang, Nicholas C. Davidson, C. Max Finlayson, Jennifer A. Gill, Robert E. Gill Jr., Patricia M. González, Tomas Gretar Gunnarsson, David Kleijn, Chris J. Spray, Tamás Székely, Des B.A. Thompson
2012, Ibis (154) 663-679
We review the conservation issues facing migratory shorebird populations that breed in temperate regions and use wetlands in the non-breeding season. Shorebirds are excellent model organisms for understanding ecological, behavioural and evolutionary processes and are often used as indicators of wetland health. A global team of experienced shorebird researchers identified...
A Gibbs sampler for Bayesian analysis of site-occupancy data
Robert M. Dorazio, Daniel Taylor Rodriguez
2012, Methods in Ecology and Evolution (3) 1093-1098
1. A Bayesian analysis of site-occupancy data containing covariates of species occurrence and species detection probabilities is usually completed using Markov chain Monte Carlo methods in conjunction with software programs that can implement those methods for any statistical model, not just site-occupancy models. Although these software programs are quite flexible, considerable...
Ball clay
R.L. Virta
2012, Mining Engineering (64) 33-34
Four companies — H.C. Spinks Clay Co., Inc., Imerys Group, Old Hickory Clay Co., and Unimin Corp. — mined ball clay in four states in 2011. Production, on the basis of preliminary data, was 940 kt (1.04 million st) with an estimated value of $44.2 million. This is a 3-percent...
Sequential development of platform to off-platform facies of the great American carbonate bank in the central Appalachians
David K. Brezinski, John F. Taylor, John E. Repetski
2012, Book chapter, The great American carbonate bank: The geology and economic resources of the Cambrian–Ordovician Sauk megasequence of Laurentia
In the central Appalachians, carbonate deposition of the great American carbonate bank began during the Early Cambrian with the creation of initial ramp facies of the Vintage Formation and lower members of the Tomstown Formation. Vertical stacking of bioturbated subtidal ramp deposits (Bolivar Heights Member) and dolomitized microbial boundtsone (Fort...
Ecology of bison, elk, and vegetation in an arid ecosystem
Kathryn A. Schoenecker
2012, Thesis
Herbivory has profound effects on vegetation production and structure in many different plant communities. The influence of herbivory on plants and ultimately ecosystem processes is shaped by the types of plants consumed, the intensity of herbivory, the evolutionary history of grazing, and the availability of water and nutrients to plants....
