Kaolin
R.L. Virta
2012, Mining Engineering (64) 70-71
Fifteen companies mined kaolin in nine states in 2011. Production, on the basis of preliminary data, was estimated to be 5.48 Mt (6.04 million st) valued at $822 million, an increase from 5.42 Mt (5.97 million st) valued at $788 million in 2010. Production in Georgia, the top producing state,...
Estimating discharge measurement uncertainty using the interpolated variance estimator
T. Cohn, J. Kiang, R. Mason Jr.
2012, Journal of Hydraulic Engineering (139) 502-510
Methods for quantifying the uncertainty in discharge measurements typically identify various sources of uncertainty and then estimate the uncertainty from each of these sources by applying the results of empirical or laboratory studies. If actual measurement conditions are not consistent with those encountered in the empirical or laboratory studies, these...
Chapter two: Phenomenology of tsunamis II: Scaling, event statistics, and inter-event triggering
Eric L. Geist
2012, Advances in Geophysics (53) 35-92
Observations related to tsunami catalogs are reviewed and described in a phenomenological framework. An examination of scaling relationships between earthquake size (as expressed by scalar seismic moment and mean slip) and tsunami size (as expressed by mean and maximum local run-up and maximum far-field amplitude) indicates that scaling is significant...
Mineral resource of the month: boron
Robert D. Crangle Jr.
2012, Earth (57) 23-23
The article offers information on the mineral, boron. Boron compounds, particularly borates, have more commercial applications than its elemental relative which is a metalloid. Making up the 90% of the borates that are used worldwide are colemanite, kernite, tincal, and ulexite. The main borate deposits are located in the Mojave...
The walk is never random: subtle landscape effects shape gene flow in a continuous white-tailed deer population in the Midwestern United States
Stacie J. Robinson, Michael D. Samuel, Davin L. Lopez, Paul Shelton
2012, Molecular Ecology (21) 4190-4205
One of the pervasive challenges in landscape genetics is detecting gene flow patterns within continuous populations of highly mobile wildlife. Understanding population genetic structure within a continuous population can give insights into social structure, movement across the landscape and contact between populations, which influence ecological interactions, reproductive dynamics or pathogen...
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....
A meeting of the waters: interdisciplinary challenges and opportunities in tidal rivers
Scott H. Ensign, Gregory B. Noe, Cliff R. Hupp, Sergio Fagherazzi
2012, Eos, Transactions, American Geophysical Union (95) 455-456
At the interface of estuarine tides and freshwater rivers lie wetland and aquatic ecosystems, which experience dramatic effects of sea level rise. There, nontidal channels and riparian floodplains are transforming into tidal ecosystems, and tidal freshwater ecosystems are receiving increasing salinity. These river-floodplain systems have both fluvial characteristics, including meandering...
Arctic shorebirds in North America: A decade of monitoring
Jonathan R. Bart, Victoria H. Johnston, editor(s)
2012, Studies in Avian Biology 44
Each year shorebirds from North and South America migrate thousands of miles to spend the summer in the Arctic. There they feed in shoreline marshes and estuaries along some of the most productive and pristine coasts anywhere. With so much available food they are able to reproduce almost explosively; and...
Genetic basis of differences in myxospore count between whirling disease-resistant and -susceptible strains of rainbow trout
Eric R. Fetherman, Dana L. Winkelman, George J. Schisler, Michael F. Antolin
2012, Diseases of Aquatic Organisms (102) 97-106
We used a quantitative genetics approach and estimated broad sense heritability (h2b) of myxospore count and the number of genes involved in myxospore formation to gain a better understanding of how resistance to Myxobolus cerebralis, the parasite responsible for whirling disease, is inherited in rainbow trout Oncorhynchus mykiss. An M....
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...
P-T-t conditions, Nd and Pb isotopic compositions and detrital zircon geochronology of the Massabesic Gneiss Complex, New Hampshire: isotopic and metamorphic evidence for the identification of Gander basement, central New England
Michael J. Dorais, Robert P. Wintsch, Michael J. Kunk, John Aleinikoff, William Burton, Christine Underdown, Charles M. Kerwin
2012, American Journal of Science (312) 1049-1097
We present new evidence for the assignment of the Neoproterozoic Massabesic Gneiss Complex of New Hampshire to the Gander terrane rather than the Avalon terrane. The majority of Avalonian (sensu stricto) igneous and meta-igneous rocks as defined in Maritime Canada have positive whole-rock ɛNd compared to more negative values for...
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...
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...
The ICDP Snake River Geothermal Drilling Project: preliminary overview of borehole geophysics
Douglas R. Schmitt, Lee M. Liberty, James E. Kessler, Jochem Kuck, Randolph Kofman, Ross Bishop, John W. Shervais, James P. Evans, Duane E. Champion
2012, Geothermal Resources Council Transactions (36) 1017-1022
Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand the geothermal systems in three locations across the Snake River Plain with varying geological and hydrological structure. An extensive series of standard and specialized geophysical logs were obtained in each of the wells. Hydrogen-index neutron and γ-γ density...
Geologic isolation of nuclear waste at high latitudes: the role of ice sheets
M. Person, J. McIntosh, N. Iverson, C. E. Neuzil, V. Bense
2012, Geofluids (12) 1-6
Geologic isolation of high-level nuclear waste from the biosphere requires special consideration in countries at high latitudes (>40°N) owing to the possibility of future episodes of continental glaciation (Talbot 1999). It is now widely recognized that Pleistocene continental glaciations have had a profound effect on rates of sediment erosion (Cuffey...
Introduced and invasive species in novel rangeland ecosystems: friends or foes?
Jayne Belnap, John A. Ludwig, Bradford P. Wilcox, Julio L. Betancourt, W. Richard J. Dean, Benjamin D. Hoffmann, Sue J. Milton
2012, Rangeland Ecology and Management (65) 569-578
Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased...
Lichens: Unexpected anti-prion agents?
Cynthia M. Rodriguez, James P. Bennett, Christopher J. Johnson
2012, Prion (6) 11-16
The prion diseases sheep scrapie and cervid chronic wasting disease are transmitted, in part, via an environmental reservoir of infectivity; prions released from infected animals persist in the environment and can cause disease years later. Central to controlling disease transmission is the identification of methods capable of inactivating these agents...
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...
A national geographic framework for guiding conservation on a landscape scale
Michael J. Millard, Craig A. Czarnecki, John M. Morton, Laura A. Brandt, Jennifer S. Briggs, Frank S. Shipley, Roger G. Sayre, Pamela J. Sponholtz, David Perkins, Darin G. Simpkins, Janith Taylor
2012, Journal of Fish and Wildlife Management (3) 175-183
The U.S. Fish and Wildlife Service, along with the global conservation community, has recognized that the conservation challenges of the 21st century far exceed the responsibilities and footprint of any individual agency or program. The ecological effects of climate change and other anthropogenic stressors do not recognize geopolitical boundaries and,...
Fold-to-fault progression of a major thrust zone revealed in horses of the North Mountain fault zone, Virginia and West Virginia, USA
Randall C. Orndorff
2012, Journal of Geological Research (2012)
The method of emplacement and sequential deformation of major thrust zones may be deciphered by detailed geologic mapping of these important structures. Thrust fault zones may have added complexity when horse blocks are contained within them. However, these horses can be an important indicator of the fault development holding information...
Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA
Joseph G. Rosenbaum, Richard L. Reynolds, Steven M. Colman
2012, Quaternary Research (78) 333-340
Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect...
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...
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...
Developing Vs30 site-condition maps by combining observations with geologic and topographic constraints
E.M. Thompson, D.J. Wald
2012, Conference Paper, The 15th World Conference on Earthquake Engineering: September 24-28, 2012, Lisbon, Portugal
Despite obvious limitations as a proxy for site amplification, the use of time-averaged shear-wave velocity over the top 30 m (VS30) remains widely practiced, most notably through its use as an explanatory variable in ground motion prediction equations (and thus hazard maps and ShakeMaps, among other applications). As such, we...
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...
