Late Quaternary paleoclimate of western Alaska inferred from fossil chironomids and its relation to vegetation histories
Joshua Kurek, Les C. Cwynar, Thomas A. Ager, Mark B. Abbott, Mary E. Edwards
2009, Quaternary Science Reviews (28) 799-811
Fossil Chironomidae assemblages (with a few Chaoboridae and Ceratopogonidae) from Zagoskin and Burial Lakes in western Alaska provide quantitative reconstructions of mean July air temperatures for periods of the late-middle Wisconsin (~39,000-34,000 cal yr B.P.) to the present. Inferred temperatures are compared with previously analyzed pollen data from each site...
Suspended sediment and carbonate transport in the Yukon River Basin, Alaska: Fluxes and potential future responses to climate change
Mark M. Dornblaser, Robert G. Striegl
2009, Water Resources Research (45)
Loads and yields of suspended sediment and carbonate were measured and modeled at three locations on the Yukon, Tanana, and Porcupine Rivers in Alaska during water years 2001–2005 (1 October 2000 to 30 September 2005). Annual export of suspended sediment and carbonate upstream from the Yukon Delta averaged 68 Mt...
Multi-offset GPR methods for hyporheic zone investigations
T.R. Brosten, J.H. Bradford, J. P. McNamara, M.N. Gooseff, J.P. Zarnetske, W.B. Bowden, M.E. Johnston
2009, Conference Paper, Near Surface Geophysics
Porosity of stream sediments has a direct effect on hyporheic exchange patterns and rates. Improved estimates of porosity heterogeneity will yield enhanced simulation of hyporheic exchange processes. Ground-penetrating radar (GPR) velocity measurements are strongly controlled by water content thus accurate measures of GPR velocity in saturated sediments provides estimates of...
Comparison with CLPX II airborne data using DMRT model
X. Xu, D. Liang, K.M. Andreadis, L. Tsang, E.G. Josberger
2009, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
In this paper, we considered a physical-based model which use numerical solution of Maxwell Equations in three-dimensional simulations and apply into Dense Media Radiative Theory (DMRT). The model is validated in two specific dataset from the second Cold Land Processes Experiment (CLPX II) at Alaska and Colorado. The data were...
Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production
J. Rutqvist, G. J. Moridis, T. Grover, T. Collett
2009, Journal of Petroleum Science and Engineering (67) 1-12
In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer...
Environmental and human influences on trumpeter swan habitat occupancy in Alaska
J.H. Schmidt, M. S. Lindberg, D.S. Johnson, J.A. Schmultz
2009, Condor (111) 266-275
Approximately 70-80% of the entire population of the Trumpeter Swan (Cygnus huccinator) depends for reproduction on wetlands in Alaska. This makes the identification of important habitat features and the effects of human interactions important for the species' long-term management. We analyzed the swan's habitat preferences in five areas throughout the...
Change in abundance of Pacific brant wintering in Alaska: Evidence of a climate warming effect?
David H. Ward, Christian P. Dau, T. Lee Tibbitts, James S. Sedinger, Betty A. Anderson, James E. Hines
2009, Arctic (62) 301-311
Winter distribution of Pacific Flyway brant (Branta bernicla nigricans) has shifted northward from low-temperate areas to sub-Arctic areas over the last 42 years. We assessed the winter abundance and distribution of brant in Alaska to evaluate whether climate warming may be contributing to positive trends in the most northern of...
Cobble cam: Grain-size measurements of sand to boulder from digital photographs and autocorrelation analyses
J.A. Warrick, D. M. Rubin, P. Ruggiero, J.N. Harney, A.E. Draut, D. Buscombe
2009, Earth Surface Processes and Landforms (34) 1811-1821
A new application of the autocorrelation grain size analysis technique for mixed to coarse sediment settings has been investigated. Photographs of sand- to boulder-sized sediment along the Elwha River delta beach were taken from approximately 1??2 m above the ground surface, and detailed grain size measurements were made from 32...
Interactive effects of fire, soil climate, and moss on CO2 fluxes in black spruce ecosystems of interior Alaska
J. A. O'Donnell, M.R. Turetsky, J.W. Harden, K.L. Manies, L.E. Pruett, G. Shetler, J. C. Neff
2009, Ecosystems (12) 57-72
Fire is an important control on the carbon (C) balance of the boreal forest region. Here, we present findings from two complementary studies that examine how fire modifies soil organic matter properties, and how these modifications influence rates of decomposition and C exchange in black spruce (Picea mariana) ecosystems of...
Multiple spring migration strategies in a population of Pacific Common Eiders
Margaret R. Petersen
2009, Condor (111) 59-70
Spring migration strategies vary within and among species. Examination of this variability extends our understanding of life histories and has implications for conservation. I used satellite transmitters to determine migration strategies and evaluate factors influencing the timing of spring migration of Pacific Common Eiders (Somateria mollissima v-nigrum) that nest along...
Genetic variation, relatedness, and effective population size of polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska
Matthew A. Cronin, Steven C. Amstrup, Sandra L. Talbot, George K. Sage, Kristin S. Amstrup
2009, Journal of Heredity (100) 681-690
Polar bears (Ursus maritimus) are unique among bears in that they are adapted to the Arctic sea ice environment. Genetic data are useful for understanding their evolution and can contribute to management. We assessed parentage and relatedness of polar bears in the southern Beaufort Sea, Alaska, with genetic data and...
Exhumation along the Fairweather fault, southeastern Alaska, based on low-temperature thermochronometry
R.J. McAleer, J.A. Spotila, E. Enkelmann, A.L. Berger
2009, Tectonics (28)
The southern Alaskan syntaxis marks the spectacular junction between the >1000-km-long Pacific-North America transform margin and the Chugach-St. Elias belt, where subduction and terrane accretion drive rapid convergent deformation and rock uplift. New low-temperature thermochronometry reveals that intense orogenic deformation is not restricted to one side of the syntaxis but...
Numerical study of tsunami generated by multiple submarine slope failures in Resurrection Bay, Alaska, during the MW 9.2 1964 earthquake
E. Suleimani, R. Hansen, Peter J. Haeussler
2009, Conference Paper, Pure and Applied Geophysics
We use a viscous slide model of Jiang and LeBlond (1994) coupled with nonlinear shallow water equations to study tsunami waves in Resurrection Bay, in south-central Alaska. The town of Seward, located at the head of Resurrection Bay, was hit hard by both tectonic and local landslide-generated tsunami waves during...
Petrology and geochronology of crustal xenoliths from the Bering Strait region: Linking deep and shallow processes in extending continental crust
V.V. Akinin, E. L. Miller, J. L. Wooden
2009, Special Paper of the Geological Society of America 39-68
Petrologic, geochemical, and metamorphic data on gneissic xenoliths derived from the middle and lower crust in the Neogene Bering Sea basalt province, coupled with U-Pb geochronology of their zircons using sensitive high-resolution ion microprobe-reverse geometry (SHRIMP-RG), yield a detailed comparison between the P-T-t and magmatic history of the lower crust...
Erosional history of Cape Halkett and contemporary monitoring of bluff retreat, Beaufort Sea coast, Alaska
Benjamin M. Jones, Christopher D. Arp, Richard A. Beck, Guido Grosse, James M. Webster, Frank E. Urban
2009, Polar Geography (32) 129-142
Cape Halkett is located along the Beaufort Sea at the end of a low-lying tundra landscape. The area has been subject to major modifications over the last century as a result of erosion and migration of the coastline inland. Long-term mean annual erosion rates (1955-2009) for the entire cape are...
Historical abundance and morphology of Didymosphenia species in Naknek Lake, Alaska
D.P. Pite, K.A. Lane, A.K. Hermann, S. A. Spaulding, B. P. Finney
2009, Conference Paper, Acta Botanica Croatica
Since the 1980s, nuisance blooms of Didymosphenia geminata (Lyngbye) M. Schmidt have been documented in sites that are warmer and more mesotrophic than historical records indicate. While the invasion of D. geminata in New Zealand is well documented, it is less clear whether nuisance blooms in North America are a...
Hierarchical spatial genetic structure of Common Eiders (Somateria mollissima) breeding along a migratory corridor
Sarah A. Sonsthagen, Sandra L. Talbot, Richard B. Lanctot, Kim T. Scribner, Kevin G. McCracken
2009, The Auk (126) 744-754
Documentation of spatial genetic discordance among breeding populations of Arctic-nesting avian species is important, because anthropogenic change is altering environmental linkages at micro- and macrogeographic scales. We estimated levels of population subdivision within Pacific Common Eiders (Somateria mollissima v-nigrum) breeding on 12 barrier islands in the western...
Interactions between soil thermal and hydrological dynamics in the response of Alaska ecosystems to fire disturbance
Shuhua Yi, A. David McGuire, Jennifer Harden, Eric Kasischke, Kristen L. Manies, Larry Hinzman, Anna K. Liljedahl, J. Randerson, Heping Liu, Vladimir E. Romanovsky, Sergey S. Marchenko, Yongwon Kim
2009, Journal of Geophysical Research: Biogeosciences (114)
Soil temperature and moisture are important factors that control many ecosystem processes. However, interactions between soil thermal and hydrological processes are not adequately understood in cold regions, where the frozen soil, fire disturbance, and soil drainage play important roles in controlling interactions among these processes. These interactions were investigated with...
Diffuse gas emissions at the Ukinrek Maars, Alaska: Implications for magmatic degassing and volcanic monitoring
William C. Evans, D. Bergfeld, R. G. McGimsey, A.G. Hunt
2009, Applied Geochemistry (24) 527-535
Diffuse CO2 efflux near the Ukinrek Maars, two small volcanic craters that formed in 1977 in a remote part of the Alaska Peninsula, was investigated using accumulation chamber measurements. High CO2 efflux, in many places exceeding 1000 g m−2 d−1, was found in conspicuous zones of plant damage or kill...
The Neoglacial landscape and human history of Glacier Bay, Glacier Bay National Park and Preserve, southeast Alaska, USA
C. Connor, G. Streveler, A. Post, D. Monteith, W. Howell
2009, Holocene (19) 381-393
The Neoglacial landscape of the Huna Tlingit homeland in Glacier Bay is recreated through new interpretations of the lower Bay's fjordal geomorphology, late Quaternary geology and its ethnographic landscape. Geological interpretation is enhanced by 38 radiocarbon dates compiled from published and unpublished sources, as well as 15 newly dated samples....
Prevalence of viral erythrocytic necrosis in Pacific herring and epizootics in Skagit Bay, Puget Sound, Washington.
P.K. Hershberger, N.E. Elder, C.A. Grady, J.L. Gregg, C.A. Pacheco, C. Greene, C. Rice, T.R. Meyers
2009, Journal of Aquatic Animal Health (21) 1-7
Epizootics of viral erythrocytic necrosis (VEN) occurred among juvenile Pacific herring Clupea pallasii in Skagit Bay, Puget Sound, Washington, during 2005-2007 and were characterized by high prevalences and intensities of cytoplasmic inclusion bodies within circulating erythrocytes. The prevalence of VEN peaked at 67% during the first epizootic in October 2005...
Implications for the dynamic health of a glacier from comparison of conventional and reference-surface balances
W.D. Harrison, L.H. Cox, R. Hock, R.S. March, E.C. Pettit
2009, Annals of Glaciology (50) 25-30
Conventional and reference-surface mass-balance data from Gulkana and Wolverine Glaciers, Alaska, USA, are used to address the questions of how rapidly these glaciers are adjusting (or 'responding') to climate, whether their responses are stable, and whether the glaciers are likely to survive in today's climate. Instability means that a glacier...
Estuarine Ecology of Juvenile Salmon in Western Alaska: a Review
Christian E. Zimmerman, Nicola Hillgruber
2009, Book chapter, American Fisheries Society Symposium
In the late 1990s and early 2000s, large declines in numbers of chum salmon Oncorhynchus keta and Chinook salmon O. tshawytscha returning to the Arctic-YukonKuskokwim (AYK) region (Alaska, USA) illuminated the need for an improved understanding of the variables controlling salmon abundance at all life stages. In addressing questions about...
Sulfur- and oxygen-isotopes in sediment-hosted stratiform barite deposits
C. A. Johnson, P. Emsbo, F. G. Poole, R. O. Rye
2009, Geochimica et Cosmochimica Acta (73) 133-147
Sulfur- and oxygen-isotope analyses have been obtained for sediment-hosted stratiform barite deposits in Alaska, Nevada, Mexico, and China to examine the environment of formation of this deposit type. The barite is contained in sedimentary sequences as old as Late Neoproterozoic and as young as Mississippian. If previously published data for...
Otters, Marine
James A. Estes, James L. Bodkin, M. Ben-David
William F. Perrin, Bernd Wursing, J.G.M. Thewissen, editor(s)
2009, Book chapter, Encyclopedia of marine mammals (second edition)
The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors....
