Bioenergetics model for estimating food requirements of female Pacific walruses (Odobenus rosmarus divergens)
S.R. Noren, Mark S. Udevitz, C.V. Jay
2012, Marine Ecology Progress Series (460) 261-275
Pacific walruses Odobenus rosmarus divergens use sea ice as a platform for resting, nursing, and accessing extensive benthic foraging grounds. The extent of summer sea ice in the Chukchi Sea has decreased substantially in recent decades, causing walruses to alter habitat use and activity patterns which could affect their energy...
Behavioral vs. molecular sources of conflict between nuclear and mitochondrial DNA: The role of male-biased dispersal in a Holarctic sea duck
Jeffrey L. Peters, Kimberly A. Bolender, John M. Pearce
2012, Molecular Ecology (21) 3562-3575
Genetic studies of waterfowl (Anatidae) have observed the full spectrum of mitochondrial (mt) DNA population divergence, from apparent panmixia to deep, reciprocally monophyletic lineages. Yet, these studies often found weak or no nuclear (nu) DNA structure, which was often attributed to male-biased gene flow, a common behaviour within this family....
Evidence of accelerated beak growth associated with avian keratin disorder in black-capped chickadees (Poecile atricapillus)
Caroline R. Van Hemert, Colleen M. Handel, Todd M. O'Hara
2012, Journal of Wildlife Diseases (48) 686-694
We recently documented an epizootic of beak deformities in more than 2,000 Black-capped Chickadees (Poecile atricapillus) and other wild bird species in North America. This emerging avian disease, which has been termed avian keratin disorder, results in gross overgrowth of the rhamphotheca, the outer, keratinized layer of the beak. To...
A multi-sensor lidar, multi-spectral and multi-angular approach for mapping canopy height in boreal forest regions
David J. Selkowitz, Gordon Green, Birgit E. Peterson, Bruce Wylie
2012, Remote Sensing of Environment (121) 458-471
Spatially explicit representations of vegetation canopy height over large regions are necessary for a wide variety of inventory, monitoring, and modeling activities. Although airborne lidar data has been successfully used to develop vegetation canopy height maps in many regions, for vast, sparsely populated regions such as the boreal forest biome,...
Analysis of low-frequency seismic signals generated during a multiple-iceberg calving event at Jakobshavn Isbræ, Greenland
Fabian Walter, Jason M. Amundson, Shad O'Neel, Martin Truffer, Mark Fahnestock, Helen A. Fricker
2012, Journal of Geophysical Research (117)
We investigated seismic signals generated during a large-scale, multiple iceberg calving event that occurred at Jakobshavn Isbræ, Greenland, on 21 August 2009. The event was recorded by a high-rate time-lapse camera and five broadband seismic stations located within a few hundred kilometers of the terminus. During the event two full-glacier-thickness...
Cenozoic tectono-thermal history of the Tordrillo Mountains, Alaska: Paleocene-Eocene ridge subduction, decreasing relief, and late Neogene faulting
Jeff A. Benowitz, Peter J. Haeussler, Paul W. Layer, Paul B. O'Sullivan, Wes K. Wallace, Robert J. Gillis
2012, Geochemistry, Geophysics, Geosystems (13)
Topographic development inboard of the continental margin is a predicted response to ridge subduction. New thermochronology results from the western Alaska Range document ridge subduction related orogenesis. K-feldspar thermochronology (KFAT) of bedrock samples from the Tordrillo Mountains in the western Alaska Range complement existing U-Pb, 40Ar/39Ar and AFT (apatite fission track)...
Predicted eelgrass response to sea level rise and its availability to foraging Black Brant in Pacific coast estuaries
Frank J. Shaughnessy, Whelan Gilkerson, Jeffrey M. Black, David H. Ward, Mark Petrie
2012, Ecological Applications (22) 1743-1761
Managers need to predict how animals will respond to habitat redistributions caused by climate change. Our objective was to model the effects of sea level rise on total eelgrass (Zostera marina) habitat area and on the amount of that area that is accessible to Brant geese (Branta bernicla), specialist grazers...
Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska
Miriam C. Jones, Guido Grosse, Benjamin M. Jones, Katey Walter Anthony
2012, Journal of Geophysical Research G: Biogeosciences (117) G00M07
Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age...
Carry-over effects of winter location contribute to variation in timing of nest initiation and clutch size in black brant (Branta bernicla nigricans)
Jason L. Schamber, James S. Sedinger, David H. Ward
2012, The Auk (129) 205-210
We assessed carry-over effects from winter location on timing of nest initiation and clutch size of Black Brant (Branta bernicla nigricans) using observations of individually marked brant breeding at the Tutakoke River colony in Alaska, and wintering along a latitudinal gradient at three areas on the Pacific coast of Baja...
Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change
Webb Miller, Stephan C. Schuster, Andreanna J. Welch, Aakrosh Ratan, Oscar C. Bedoya-Reina, Fangqing Zhao, Hie Lim Kim, Richard C. Burhans, Daniela I. Drautz, Nicola E. Wittekindt, Lynn P. Tomsho, Enrique Ibarra-Laclette, Luis Herrera-Estrella, Elizabeth L. Peacock, Sean Farley, George K. Sage, Karyn D. Rode, Martyn E. Obbard, Rafael Montiel, Lutz Bachmann, Ólafur Ingólfsson, Jon Aars, Thomas Mailund, Øystein Wiig, Sandra L. Talbot, Charlotte Lindqvist
2012, Proceedings of the National Academy of Sciences (109) E2382-E2390
Polar bears (PBs) are superbly adapted to the extreme Arctic environment and have become emblematic of the threat to biodiversity from global climate change. Their divergence from the lower-latitude brown bear provides a textbook example of rapid evolution of distinct phenotypes. However, limited mitochondrial and nuclear DNA evidence conflicts in...
Soil data for a collapse-scar bog chronosequence in Koyukuk Flats National Wildlife Refuge, Alaska, 2008
Jonathan A. O’Donnell, Jennifer W. Harden, Kristen L. Manies, M. Torre Jorgenson
2012, Open-File Report 2012-1230
Peatlands in the northern permafrost region store large amounts of organic carbon, most of which is currently stored in frozen peat deposits. Recent warming at high-latitudes has accelerated permafrost thaw in peatlands, which will likely result in the loss of soil organic carbon from previously frozen peat deposits to the...
Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Badakhshan mineral district in Afghanistan: Chapter F in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan
Philip A. Davis, Scott A. Arko, Michelle L. Harbin
2012, Data Series 709-F
The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the...
Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Aynak mineral district in Afghanistan: Chapter E in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan
Philip A. Davis, Laura E. Cagney, Scott A. Arko, Michelle L. Harbin
2012, Data Series 709-E
The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the...
Evaluation of streambed scour at bridges over tidal waterways in Alaska
Jeffrey S. Conaway, Paul V. Schauer
2012, Scientific Investigations Report 2012-5245
The potential for streambed scour was evaluated at 41 bridges that cross tidal waterways in Alaska. These bridges are subject to several coastal and riverine processes that have the potential, individually or in combination, to induce streambed scour or to damage the structure or adjacent channel. The proximity of a...
Phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata) and White-winged Scoters (Melanitta fusca) on the Pacific coast of North America
Rian D. Dickson, Daniel Esler, Jerry W. Hupp, E.M. Anderson, J.R. Evenson, J. Barrett
2012, Canadian Journal of Zoology (90) 932-944
By quantifying phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata (L., 1758)) and White-winged Scoters (Melanitta fusca (L., 1758)), we tested whether timing of moult is dictated by temporal optima or constraints. Scoters (n = 3481) were captured during moult in Alaska, British Columbia, and Washington, and...
Assessment of undiscovered petroleum resources of the Arctic Alaska Petroleum Province
David W. Houseknecht, Kenneth J. Bird, Christopher P. Garrity
2012, Scientific Investigations Report 2012-5147
The Arctic Alaska Petroleum Province encompasses all lands and adjacent continental shelf areas north of the Brooks Range-Herald arch tectonic belts and south of the northern (outboard) margin of the Alaska rift shoulder. Even though only a small part is thoroughly explored, it is one of the most prolific petroleum...
Assessment of undiscovered petroleum resources of the Amerasia Basin Petroleum Province
David W. Houseknecht, Kenneth J. Bird, Christopher P. Garrity
2012, Scientific Investigations Report 2012-5146
The Amerasia Basin Petroleum Province encompasses the Canada Basin and the sediment prisms along the Alaska and Canada margins, outboard from basinward margins (hingelines) of the rift shoulders that formed during extensional opening of the Canada Basin. The province includes the Mackenzie delta and slope, the outer shelves and marine...
Early Tertiary exhumation of the flank of a forearc basin, southwest Talkeetna Mountains, Alaska
Heather A. Bleick, Alison B. Till, Dwight Bradley, Paul O’Sullivan, Joe L. Wooden, Dan B. Bradley, Theresa A. Taylor, Sam B. Friedman, Chad P. Hults
2012, Open-File Report 2012-1232
New geochronologic and thermochronologic data from rocks near Hatcher Pass, southwest Talkeetna Mountains, Alaska, record earliest Paleocene erosional and structural exhumation on the flank of the active Cook Inlet forearc basin. Cretaceous plutons shed sediments to the south, forming the Paleocene Arkose Ridge Formation. A Paleocene(?)-Eocene detachment fault juxtaposed ~60...
Polar bear and walrus response to the rapid decline in Arctic sea ice
Karen L. Oakley, Mary E. Whalen, David C. Douglas, Mark S. Udevitz, Todd C. Atwood, C. Jay
2012, Fact Sheet 2012-3131
The Arctic is warming faster than other regions of the world due to positive climate feedbacks associated with loss of snow and ice. One highly visible consequence has been a rapid decline in Arctic sea ice over the past 3 decades - a decline projected to continue and result in...
Walrus areas of use in the Chukchi Sea during sparse sea ice cover
Chadwick V. Jay, Anthony S. Fischbach, Anatoly A. Kochnev
2012, Marine Ecology Progress Series (468) 1-13
The Pacific walrus Odobenus rosmarus divergens feeds on benthic invertebrates on the continental shelf of the Chukchi and Bering Seas and rests on sea ice between foraging trips. With climate warming, ice-free periods in the Chukchi Sea have increased and are projected to increase further in frequency and duration. We...
The United States National Climate Assessment - Alaska Technical Regional Report
Carl J. Markon, Sarah F. Trainor, F. Stuart Chapin III
Carl J. Markon, Sarah F. Trainor, F. Stuart Chapin III, editor(s)
2012, Circular 1379
The Alaskan landscape is changing, both in terms of effects of human activities as a consequence of increased population, social and economic development and their effects on the local and broad landscape; and those effects that accompany naturally occurring hazards such as volcanic eruptions, earthquakes, and tsunamis. Some of the...
Cambrian–Ordovician sedimentary rocks of Alaska
Julie A. Dumoulin, Anita G. Harris
James R. Derby, S.A. Longacre, William A. Morgan, C.A. Sternbach, editor(s)
2012, Book chapter, The great American carbonate bank: The geology and economic resources of the Cambrian-Ordovician Sauk megasequence of Laurentia
Cambrian-Lower Ordovician carbonate rocks that likely formed as part of the Laurentian continental margin, and may thus have been part of the Cambrian-Ordovician great American carbonate bank, occur in east-central Alaska in the Nation Arch area. These strata accumulated on the southwestern margin (present-day coordinates) of the Yukon stable block,...
Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan
Philip A. Davis
2012, Data Series 709
The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the...
Studies by the U.S. Geological Survey in Alaska, 2011
Julie A. Dumoulin, Cynthia Dusel-Bacon
2012, Professional Paper 1795
The collection of papers that follow continues the series of U.S. Geological Survey (USGS) investigative reports in Alaska under the broad umbrella of the geologic sciences. This series represents new and sometimes-preliminary findings that are of interest to Earth scientists in academia, government, and industry; to land and resource managers;...
Geologic map of the Cook Inlet region, Alaska, including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale quadrangles
Frederic H. Wilson, Chad P. Hults, Henry R. Schmoll, Peter J. Haeussler, Jeanine M. Schmidt, Lynn A. Yehle, Keith A. Labay
2012, Scientific Investigations Map 3153
In 1976, L.B. Magoon, W.L. Adkinson, and R.M. Egbert published a major geologic map of the Cook Inlet region, which has served well as a compilation of existing information and a guide for future research and mapping. The map in this report updates Magoon and others (1976) and incorporates new...
