Assessing the validity of station location assumptions made in the calculation of the geomagnetic disturbance index, Dst
Jennifer Gannon
2012, Space Weather (10)
In this paper, the effects of the assumptions made in the calculation of the Dst index with regard to longitude sampling, hemisphere bias, and latitude correction are explored. The insights gained from this study will allow operational users to better understand the local implications of the Dst index and will...
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...
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...
Constraints on the history and topography of the Northeastern Sierra Nevada from a Neogene sedimentary basin in the Reno-Verdi area, Western Nevada
James Trexler, Patricia Cashman, Michael Cosca
2012, Geosphere (8) 548-561
Neogene (Miocene–Pliocene) sedimentary rocks of the northeastern Sierra Nevada were deposited in small basins that formed in response to volcanic and tectonic activity along the eastern margin of the Sierra. These strata record an early phase (ca. 11–10 Ma) of extension and rapid sedimentation of boulder conglomerates and debrites deposited...
History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010
David B. Smith, William F. Cannon, Laurel G. Woodruff, Francisco Moreira Rivera, Andrew N. Rencz, Robert G. Garrett
2012, Earth Science Frontiers (19) 19-32
In 2007, the U.S. Geological Survey, the Geological Survey of Canada, and the Mexican Geological Survey initiated a low-density (1 site per 1600 km2, 13323 sites) geochemical and mineralogical survey of North American soils (North American Soil Geochemical Landscapes Project). Sampling and analytical protocols were developed at a series of...
Deep Arctic Ocean warming during the last glacial cycle
T. M. Cronin, G. S. Dwyer, J. Farmer, H.A. Bauch, R.F. Spielhagen, M. Jakobsson, J. Nilsson, W. M. Briggs Jr., A. Stepanova
2012, Nature Geoscience (5) 631-634
In the Arctic Ocean, the cold and relatively fresh water beneath the sea ice is separated from the underlying warmer and saltier Atlantic Layer by a halocline. Ongoing sea ice loss and warming in the Arctic Ocean have demonstrated the instability of the halocline, with implications for further sea ice...
Alaska's rare earth deposits and resource potential
James C. Barker, Bradley S. Van Gosen
2012, Mining Engineering (64) 20-32
Alaska’s known mineral endowment includes some of the largest and highest grade deposits of various metals, including gold, copper and zinc. Recently, Alaska has also been active in the worldwide search for sources of rare earth elements (REE) to replace exports now being limitedby China. Driven by limited supply of...
Assessing California groundwater susceptibility using trace concentrations of halogenated volatile organic compounds
Daniel A. Deeds, Justin T. Kulongoski, Kenneth Belitz
2012, Environmental Science & Technology (46) 13128-13135
Twenty-four halogenated volatile organic compounds (hVOCs) and SF6 were measured in groundwater samples collected from 312 wells across California at concentrations as low as 10–12 grams per kilogram groundwater. The hVOCs detected are predominately anthropogenic (i.e., “ahVOCs”) and as such their distribution delineates where groundwaters are impacted and susceptible to...
Effects of low-density feeding on elk–fetus contact rates on Wyoming feedgrounds
Tyler G. Creech, Paul C. Cross, Brandon M. Scurlock, Eric Maichak, Jared D. Rogerson, John C. Henningsen, Scott Creel
2012, Journal of Wildlife Management (76) 877-886
High seroprevalance for Brucella abortus among elk on Wyoming feedgrounds suggests that supplemental feeding may influence parasite transmission and disease dynamics by altering the rate at which elk contact infectious materials in their environment. We used proximity loggers and video cameras to estimate rates of elk-to-fetus contact (the primary source...
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...
How many records should be used in ASCE/SEI-7 ground motion scaling procedure?
Juan C. Reyes, Erol Kalkan
2012, Earthquake Spectra (28) 1223-1242
U.S. national building codes refer to the ASCE/SEI-7 provisions for selecting and scaling ground motions for use in nonlinear response history analysis of structures. Because the limiting values for the number of records in the ASCE/SEI-7 are based on engineering experience, this study examines the required number of records statistically,...
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 terrestrial lidar-based workflow for determining three-dimensional slip vectors and associated uncertainties
Peter O. Gold, Eric Cowgill, Oliver Kreylos, Ryan D. Gold
2012, Geosphere (8) 431-442
Three-dimensional (3D) slip vectors recorded by displaced landforms are difficult to constrain across complex fault zones, and the uncertainties associated with such measurements become increasingly challenging to assess as landforms degrade over time. We approach this problem from a remote sensing perspective by using terrestrial laser scanning (TLS) and 3D...
Avian botulism and avian chlamydiosis in wild water birds, Benton Lake National Wildlife Refuge, Montana, USA
Douglas E. Docherty, J. Christian Franson, Roger E. Brannian, Renee R. Long, Craig A. Radi, David Krueger, Robert F. Johnson
2012, Journal of Zoo and Wildlife Medicine (43) 885-888
In 1999, the U.S. Geological Survey (USGS) National Wildlife Health Center, Madison, Wisconsin, conducted a diagnostic investigation into a water bird mortality event involving intoxication with avian botulism type C and infection with avian chlamydiosis at the Benton Lake National Wildlife Refuge in Montana, USA. Of 24 carcasses necropsied, 11...
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...
New insights into gill ionocyte and ion transporter function in euryhaline and diadromous fish
Junya Hiroi, Stephen D. McCormick
2012, Respiratory Physiology and Neurobiology (184) 257-268
Teleost fishes are able to acclimatize to seawater by secreting excess NaCl by means of specialized “ionocytes” in the gill epithelium. Antibodies against Na+/K+-ATPase (NKA) have been used since 1996 as a marker for identifying branchial ionocytes. Immunohistochemistry of NKA by itself and in combination with Na+/K+/2Cl− cotransporter and CFTR...
Post-fire land treatments and wind erosion -- lessons from the Milford Flat Fire, UT, USA
Mark E. Miller, Matthew A. Bowker, Richard L. Reynolds, Harland L. Goldstein
2012, Aeolian Research (7) 29-44
We monitored sediment flux at 25 plots located at the northern end of the 2007 Milford Flat Fire (Lake Bonneville Basin, west-central Utah) to examine the effectiveness of post-fire rehabilitation treatments in mitigating risks of wind erosion during the first 3 years post fire. Maximum values were recorded during Mar–Jul...
Data quality of seismic records from the Tohoku, Japan earthquake as recorded across the Albuquerque Seismological Laboratory networks
A. T. Ringler, L.S. Gee, B. Marshall, C. R. Hutt, T. Storm
2012, Seismological Research Letters (83) 575-584
Great earthquakes recorded across modern digital seismographic networks, such as the recent Tohoku, Japan, earthquake on 11 March 2011 (Mw = 9.0), provide unique datasets that ultimately lead to a better understanding of the Earth's structure (e.g., Pesicek et al. 2008) and earthquake sources (e.g., Ammon et al. 2011). For...
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...
Effects of climate change and population growth on the transboundary Santa Cruz aquifer
Christopher A. Scott, Sharon Megdal, Lucas Antonio Oroz, James Callegary, Prescott Vandervoet
2012, Climate Research (51) 159-170
The USA and Mexico have initiated comprehensive assessment of 4 of the 18 aquifers underlying their 3000 km border. Binational management of groundwater is not currently proposed. University and agency researchers plus USA and Mexican federal, state, and local agency staff have collaboratively identified key challenges facing the Santa Cruz...
John B. "Jack" Townshend (1927-2012)
Jeffrey J. Love, Carol A. Finn
2012, Eos, Transactions, American Geophysical Union (93) 524-525
Jack Townshend, geophysicist and dedicated public servant, died on 13 August 2012 in Fairbanks, Alaska. He was 85. Jack's career with the federal government, most of it with the national magnetic observatory program, spanned more than six solar cycles of time, and he retired only days before his death. The...
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...
Industrial garnet
D.W. Olson
2012, Mining Engineering (64) 64-64
Garnet has been used as a gemstone since the Bronze Age. However, garnet's angular fractures, relatively high hardness and specific gravity, chemical inertness, and nontoxicity make it ideal for many industrial applications. It is also free of crystalline silica and can be recycled....
Developing ShakeCast statistical fragility analysis framework for rapid post-earthquake assessment
K.-W. Lin, D.J. Wald
2012, Conference Paper, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon, Portugal, September 24-28
When an earthquake occurs, the U. S. Geological Survey (USGS) ShakeMap estimates the extent of potentially damaging shaking and provides overall information regarding the affected areas. The USGS ShakeCast system is a freely-available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users’...
Abiotic and biotic controls of cryptobenthic fish assemblages across a Caribbean seascape
A.R. Harborne, H.L. Jelks, W. F. Smith-Vaniz, L.A. Rocha
2012, Coral Reefs (31) 977-990
The majority of fish studies on coral reefs consider only non-cryptic species and, despite their functional importance, data on cryptic species are scarce. This study investigates inter-habitat variation in Caribbean cryptobenthic fishes by re-analysing a comprehensive data set from 58 rotenone stations around Buck Island, U.S. Virgin Islands. Boosted regression...
