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: 2891
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 probability p
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
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, and ecosys
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
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 McAfee et al. W
Authors
Jeremy Littell, Stephanie A. McAfee, Gregory D. Hayward
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 data. Hence
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
Body size and lean mass of brown bears across and within four diverse ecosystems
Variation in body size across populations of brown bears (Ursus arctos) is largely a function of the availability and quality of nutritional resources while plasticity within populations reflects utilized niche width with implications for population resiliency. We assessed skull size, body length, and lean mass of adult female and male brown bears in four Alaskan study areas that differed in clim
Authors
Grant V. Hilderbrand, David Gustine, Buck A. Mangipane, Kyle Joly, William Leacock, Lindsey S. Mangipane, Joy Erlenbach, Mathew Sorum, Matthew Cameron, Jerrold L. Belant, Troy Cambier
Design considerations for estimating survival rates with standing age structures
Survival rate estimates are critical to understanding the dynamics and status of a population, and
they are often inferred from samples of the population’s age structure. A recently developed method uses time
series of standing age-structure data with information about population growth rate or fecundity to provide
explicit maximum likelihood estimators of age-specific survival rates, without assu
Authors
Rebecca L. Taylor, Mark S. Udevitz
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 prey by co
Authors
Sarah M. Laske, Amanda E. Rosenberger, Mark S. Wipfli, Christian E. Zimmerman
Biological responses of Crested and Least auklets to volcanic destruction of nesting habitat in the Aleutian Islands, Alaska
Crested Auklets (Aethia cristatella) and Least Auklets (A. pusilla) are crevice-nesting birds that breed in large mixed colonies at relatively few sites in the Aleutian Island archipelago, Bering Sea, Gulf of Alaska, and Sea of Okhotsk. Many of these colonies are located on active volcanic islands. The eruption of Kasatochi volcano, in the central Aleutians, on August 7, 2008, completely buried al
Authors
Gary S. Drew, John F. Piatt, Jeffrey C. Williams
Development and characterization of 12 polymorphic microsatellite loci in the sea sandwort, Honckenya peploides
Codominant marker systems are better suited to analyze population structure and assess the source of an individual in admixture analyses. Currently, there is no codominant marker system using microsatellites developed for the sea sandwort, Honckenya peploides (L.) Ehrh., an early colonizer in island systems. We developed and characterized novel microsatellite loci from H. peploides, using reads co
Authors
Megan C. Gravley, George K. Sage, Sandra L. Talbot, Matthew L. Carlson
A comparison of photograph-interpreted and IfSAR-derived maps of polar bear denning habitat for the 1002 Area of the Arctic National Wildlife Refuge, Alaska
Polar bears (Ursus maritimus) in Alaska use the Arctic National Wildlife Refuge (ANWR) for maternal denning. Pregnant bears den in snow banks for more than 3 months in winter during which they give birth to and nurture young. Denning is one of the most vulnerable times in polar bear life history as the family group cannot simply walk away from a disturbance without jeopardizing survival of newly b
Authors
George M. Durner, Todd C. Atwood
Acquisition and dissemination of cephalosporin-resistant E. coli in migratory birds sampled at an Alaska landfill as inferred through genomic analysis
Antimicrobial resistance (AMR) in bacterial pathogens threatens global health, though the spread of AMR bacteria and AMR genes between humans, animals, and the environment is still largely unknown. Here, we investigated the role of wild birds in the epidemiology of AMR Escherichia coli. Using next-generation sequencing, we characterized cephalosporin-resistant E. coli cultured from sympatric gulls
Authors
Christina Ann Ahlstrom, Jonas Bonnedahl, Hanna Woksepp, Jorge Hernandez, Olsen Bjorn, Andrew M. Ramey
A snow density dataset for improving surface boundary conditions in Greenland ice sheet firn modeling
The surface snow density of glaciers and ice sheets is of fundamental importance in converting volume to mass in both altimetry and surface mass balance studies, yet it is often poorly constrained. Site-specific surface snow densities are typically derived from empirical relations based on temperature and wind speed. These parameterizations commonly calculate the average density of the top meter o
Authors
Robert Fausto, Jason E. Box, Baptiste Vandecrux, Dirk van As, Konrad Steffen, Michael J. MacFerrin, Horst Machguth, William Colgan, Daniel Mcgrath, Lora S. Koenig, Charalampos Charalampidis, Roger J. Braithwaite