Publications
USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.
Filter Total Items: 3087
Evolving environmental and geometric controls on Columbia Glacier’s continued retreat Evolving environmental and geometric controls on Columbia Glacier’s continued retreat
Geometry strongly controls the dynamic behavior of marine‐terminating (tidewater) glaciers, significantly influencing advance and retreat cycles independent of climate. Yet the recent, nearly ubiquitous retreat of tidewater glaciers suggests that changes in atmospheric and oceanic forcing may also drive dynamic change. To isolate the influence of geometry on tidewater glacier dynamics...
Authors
Ellyn Enderlin, Shad O’Neel, Timothy C. Bartholomaus, Ian Joughin
Ongoing bedrock incision of the Fortymile River driven by Pliocene–Pleistocene Yukon River capture, eastern Alaska, USA, and Yukon, Canada Ongoing bedrock incision of the Fortymile River driven by Pliocene–Pleistocene Yukon River capture, eastern Alaska, USA, and Yukon, Canada
Quantification of river incision via process rate laws represents a key goal of geomorphic research, but such models often fail to reproduce traits of natural rivers responding to base-level lowering. The Fortymile River flows from eastern Alaska in the United States to the Yukon River in Canada across a tectonically quiescent region with near-uniform precipitation and bedrock erosivity...
Authors
Adrian Bender, Richard O. Lease, Lee B. Corbett, Paul R. Bierman, Marc Caffee
Mean composite fire severity metrics computed with Google Earth Engine offer improved accuracy and expanded mapping potential Mean composite fire severity metrics computed with Google Earth Engine offer improved accuracy and expanded mapping potential
Landsat-based fire severity datasets are an invaluable resource for monitoring and research purposes. These gridded fire severity datasets are generally produced with pre-and post-fire imagery to estimate the degree of fire-induced ecological change. Here, we introduce methods to produce three Landsat-based fire severity metrics using the Google Earth Engine (GEE) platform: the delta...
Authors
Sean Parks, Lisa M. Holsinger, Morgan Voss, Rachel A. Loehman, Nathaniel P. Robinson
Variation in age ratio of midcontinent greater white-fronted geese during fall migration Variation in age ratio of midcontinent greater white-fronted geese during fall migration
Annual productivity is an important parameter for the management of waterfowl populations. Fall age ratio (juveniles:total birds) is an index of productivity of the preceding breeding season. However, differences in the timing of migration between family groups and nonbreeding birds may bias age-ratio estimates. We examined temporal variation in age ratios of midcontinent greater white...
Authors
Wade G. Schock, Julian B. Fischer, Craig R. Ely, Robert A. Stehn, Jeffery M. Welker, Douglas Causey
A multi-species synthesis of satellite telemetry data in the Pacific Arctic (1987–2015): Overlap of marine mammal distributions and core use areas A multi-species synthesis of satellite telemetry data in the Pacific Arctic (1987–2015): Overlap of marine mammal distributions and core use areas
We collated available satellite telemetry data for six species of ice-associated marine mammals in the Pacific Arctic: ringed seals (Pusa hispida; n = 118), bearded seals(Erignathus barbatus, n = 51), spotted seals (Phoca largha, n = 72), Pacific walruses (Odobenus rosmarus divergens, n = 389); bowhead whales (Balaena mysticetus, n = 46), and five Arctic and sub-arctic stocks of beluga...
Authors
John J. Citta, Lloyd F. Lowry, Lori T. Quakenbush, Brendan P. Kelly, Anthony S. Fischbach, Josh M. London, Chadwick V. Jay, Kathryn J. Frost, Gregory O’Corry Crowe, Justin A. Crawford, Peter L. Boveng, Michael Cameron, Andrew L. Von Duyke, Mark Nelson, Lois A. Harwood, Pierre Richard, Robert Suydam, Mads Peter Heide-Jorgensen, Roderick C. Hobbs, Dennis I. Litovka, Marianne Marcoux, Alex Whiting, Amy S. Kennedy, John C. George, Jack Orr, Tom Gray
Whole-genome analysis of Mustela erminea finds that pulsed hybridization impacts evolution at high latitudes Whole-genome analysis of Mustela erminea finds that pulsed hybridization impacts evolution at high latitudes
At high latitudes, climatic shifts hypothetically initiate recurrent episodes of divergence by isolating populations in glacial refugia—ice-free regions that enable terrestrial species persistence. Upon glacial recession, populations subsequently expand and often come into contact with other independently diverging populations, resulting in gene flow. To understand how recurrent periods...
Authors
Jocelyn P. Colella, Tianying Lan, Stephen C. Schuster, Sandra L. Talbot, Joseph A. Cook, Charlotte Lindqvist
Remotely sensing the morphometrics and dynamics of a cold region dune field using historical aerial photography and airborne LiDAR data Remotely sensing the morphometrics and dynamics of a cold region dune field using historical aerial photography and airborne LiDAR data
This study uses an airborne Light Detection and Ranging (LiDAR) survey, historical aerial photography and historical climate data to describe the character and dynamics of the Nogahabara Sand Dunes, a sub-Arctic dune field in interior Alaska’s discontinuous permafrost zone. The Nogahabara Sand Dunes consist of a 43-km2 area of active transverse and barchanoid dunes within a 3200-km2 area...
Authors
Carson Baughman, Benjamin M. Jones, Karin L. Bodony, Daniel H. Mann, Christopher F. Larsen, Emily A. Himmelstoss, Jeremy Smith
The Mystic subterrane (partly) demystified: New data from the Farewell terrane and adjacent rocks, interior Alaska The Mystic subterrane (partly) demystified: New data from the Farewell terrane and adjacent rocks, interior Alaska
The youngest part of the Farewell terrane in interior Alaska (USA) is the enigmatic Devonian–Cretaceous Mystic subterrane. New U-Pb detrital zircon, fossil, geochemical, neodymium isotopic, and petrographic data illuminate the origin of the rocks of this subterrane. The Devonian–Permian Sheep Creek Formation yielded youngest detrital zircons of Devonian age, major detrital zircon age...
Authors
Julie A. Dumoulin, James V. Jones, Stephen E. Box, Dwight Bradley, Robert A. Ayuso, Paul B. O’Sullivan
Tundra be dammed: Beaver colonization of the Arctic Tundra be dammed: Beaver colonization of the Arctic
Increasing air temperatures are changing the arctic tundra biome. Permafrost is thawing, snow duration is decreasing, shrub vegetation is proliferating, and boreal wildlife is encroaching. Here we present evidence of the recent range expansion of North American beaver (Castor canadensis) into the Arctic, and consider how this ecosystem engineer might reshape the landscape, biodiversity...
Authors
Ken D. Tape, Benjamin M. Jones, Christopher D. Arp, Ingemar Nitze, Guido Grosse
Alaska snowpack response to climate change: Statewide snowfall equivalent and snowpack water scenarios Alaska snowpack response to climate change: Statewide snowfall equivalent and snowpack water scenarios
Climatically driven changes in snow characteristics (snowfall, snowpack, and snowmelt) will affect hydrologic and ecological systems in Alaska over the coming century, yet there exist no projections of downscaled future snow pack metrics for the state of Alaska. We updated historical and projected snow day fraction (PSF, the fraction of days with precipitation falling as snow) from...
Authors
Jeremy S. Littell, Stephanie A. McAfee, Gregory D. Hayward
Slope failure and mass transport processes along the Queen Charlotte Fault, southeastern Alaska Slope failure and mass transport processes along the Queen Charlotte Fault, southeastern Alaska
The Queen Charlotte Fault defines the Pacific–North America transform plate boundary in western Canada and southeastern Alaska for c. 900 km. The entire length of the fault is submerged along a continental margin dominated by Quaternary glacial processes, yet the geomorphology along the margin has never been systematically examined due to the absence of high-resolution seafloor mapping...
Authors
Daniel Brothers, Brian D. Andrews, Maureen A. L. Walton, H. Gary Greene, J. Vaughn Barrie, Nathaniel C. Miller, Uri S. ten Brink, Amy E. East, Peter J. Haeussler, Jared W. Kluesner, James E. Conrad
Generalist feeding strategies in Arctic freshwater fish: A mechanism for dealing with extreme environments Generalist feeding strategies in Arctic freshwater fish: A mechanism for dealing with extreme environments
Generalist feeding strategies are favoured in stressful or variable environments where flexibility in ecological traits is beneficial. Species that feed across multiple habitat types and trophic levels may impart stability on food webs through the use of readily available, alternative energy pools. In lakes, generalist fish species may take advantage of spatially and temporally variable...
Authors
Sarah M. Laske, Amanda E. Rosenberger, Mark S. Wipfli, Christian E. Zimmerman