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
Intrapopulation differences in polar bear movement and step selection patterns
BackgroundThe spatial ecology of individuals often varies within a population or species. Identifying how individuals in different classes interact with their environment can lead to a better understanding of population responses to human activities and environmental change and improve population estimates. Most inferences about polar bear (Ursus maritimus) spatial ecology are based on data from a
Authors
Ryan R. Wilson, Michelle St Martin, Eric V. Regehr, Karyn D. Rode
How beavers are changing Arctic landscapes and Earth’s climate
Beavers build dams that change the way water moves between streams, lakes, and the land. In Alaska, beavers are moving north from the forests into the Arctic tundra. When beavers build dams in the Arctic, they cause frozen soil, called permafrost, to thaw. Scientists are studying how beavers and the thawing of permafrost are impacting streams and rivers in Alaska’s national parks. For example, per
Authors
Jonathan A. O'Donnell, Michael P. Carey, Brett Poulin, Ken Tape, Joshua C. Koch
Comparison of indices to infer population dynamics of black brant
To aid managers in assessing status of Pacific black brant Branta bernicla nigricans (hereafter brant), I examined pre-existing long-term data series from summer, fall staging, and wintering areas to infer overall population processes and assessed the utility of the various data sources. Variation in demographic parameters measured in subarctic and Arctic locations suggests some form of metapopula
Authors
Paul L. Flint
Fish ear stones offer climate change clues in Alaska's lakes
Otoliths, also known as ear stones, are small body parts that help fish with hearing and balance. Like tree rings, otoliths form one light and one dark band per year, creating rings. These rings can be measured to understand fish growth. The wider the ring, the greater the growth. In our study, we used otoliths to understand how one fish species—lake trout—responds to rising temperature in the sta
Authors
Krista K. Bartz, Vanessa R. von Biela, Bryan A. Black, Daniel B. Young, Peter van der Sleen, Christian E. Zimmerman
Geospatial analysis delineates lode gold prospectivity in Alaska
Comprehensive, data-driven geographic information system analyses utilize publicly available lithologic, geochemical, geophysical, and mineral occurrence datasets to delineate gold resource potential in Alaska. These prospectivity analyses successfully identify areas containing known lode gold occurrences, expand areas of high prospectivity around known occurrences, improve the precision of deline
Authors
Susan M. Karl, Douglas C. Kreiner, George N. D. Case, Keith A. Labay
A collaborative agenda for archaeology and fire science
Humans have influenced global fire activity for millennia and will continue to do so into the future. Given the long-term interaction between humans and fire, we propose a collaborative research agenda linking archaeology and fire science that emphasizes the socioecological histories and consequences of anthropogenic fire in the development of fire management strategies today.
Authors
Grant J. Snitker, Christopher Roos, Allen Sullivan, S. Yoshi Maezumi, Douglas Bird, Michael Coughlan, Kelly Derr, Linn Gassaway, Anna Klimaszewski-Patterson, Rachel A. Loehman
Marine mammal hotspots across the circumpolar Arctic
AimIdentify hotspots and areas of high species richness for Arctic marine mammals.LocationCircumpolar Arctic.MethodsA total of 2115 biologging devices were deployed on marine mammals from 13 species in the Arctic from 2005 to 2019. Getis-Ord Gi* hotspots were calculated based on the number of individuals in grid cells for each species and for phylogenetic groups (nine pinnipeds, three cetaceans, a
Authors
Charmain Hamilton, Christian Lydersen, Jon Aars, Mario Acquarone, Todd C. Atwood, Alastair Baylis, Martin Biuw, Andrei N. Boltunov, Erik W. Born, Peter L. Boveng, Tanya M. Brown, Michael Cameron, John J. Citta, Justin A. Crawford, Rune Dietz, Jim Elias, Steven H. Ferguson, Aaron T. Fisk, Lars P. Folkow, Kathryn J. Frost, Dmitri M. Glazov, Sandra M. Granquist, Rowenna Gryba, Lois A. Harwood, Tore Haug, Mads Peter Heide-Jørgensen, Nigel E. Hussey, Jimmy Kalinek, Kristin L. Laidre, Dennis I. Litovka, Josh M. London, Lisa Loseto, Shannon MacPhee, Marianne Marcoux, Cory J. D. Matthews, Kjell J Nilssen, Erling S. Nordøy, Greg O’Corry-Crowe, Nils Øien, Morten Tange Olsen, Lori T. Quakenbush, Aqqalu Rosing-Asvid, Varvara Semenova, Kim E. W. Shelden, Olga V. Shpak, Garry Stenson, Luke Storrie, Signe Sveegaard, Jonas Teilmann, Fernando Ugarte, Andrew L. Von Duyke, Cortney Watt, Øystein Wiig, Ryan R. Wilson, David J. Yurkowski, Kit M. Kovacs
Laurentia in transition during the Mesoproterozoic: Observations and speculation on the ca. 1500–1340 Ma tectonic evolution of the southern Laurentian margin
An accretionary tectonic model for the Mesoproterozoic ca. 1500–1340 Ma tectonic evolution of the southern Laurentian margin is presented. The tectonic model incorporates key observations about the nature and timing of Mesoproterozoic deposition, magmatism, regional metamorphism, and deformation across the 5000-km-long southern Laurentian margin. This time period was one of transition in the super
Authors
Christopher G. Daniel, Ruth Aronoff, Aphrodite Indares, James V. Jones
Circa 1.50–1.45 Ga metasedimentary rocks in southwestern Laurentia provide distinctive records of Mesoproterozoic regional orogenesis and craton interactions
The discovery of multiple deformed and metamorphosed sedimentary successions in southwestern Laurentia that have depositional ages between ca. 1.50 and 1.45 Ga marked a turning point in our understanding of the Mesoproterozoic tectonic evolution of the continent and its interactions with formerly adjacent cratons. Detrital zircon U-Pb ages from metasedimentary strata and igneous U-Pb zircon ages f
Authors
James V. Jones, Christopher G. Daniel
Topographic controls on ice flow and recession for Juneau Icefield (Alaska/British Columbia)
Globally, mountain glaciers and ice caps are losing dramatic volumes of ice. The resultant sea-level rise is dominated by contributions from Alaska. Plateau icefields may be especially sensitive to climate change due to the non-linear controls their topography imparts on their response to climate change. However, Alaskan plateau icefields have been subject to little structural glaciological or reg
Authors
Bethan Davies, Jacob Bendle, Jonathan Carrivick, Robert McNabb, Christopher J. McNeil, Mauri Pelto, Seth Campbell, Tom Holt, Jeremy Ely, Bradley Markle
Climate and landscape controls on old-growth western juniper demography in the northern Great Basin, USA
Western juniper (Juniperus occidentalis Hook.) woodlands have persisted for millennia in semiarid parts of the northern Great Basin, USA, providing critical habitat for plant and animal species. Historical records suggest that the establishment of western juniper is strongly associated with regional climatic variability. For example, the abundance of western juniper pollen and macrofossils measure
Authors
Rachel A. Loehman, Emily K. Heyerdahl, Gregory T. Pederson, David B. McWethy
Sensitivity of headwater streamflow to thawing permafrost and vegetation change in a warming Arctic
Climate change has the potential to impact headwater streams in the Arctic by thawing permafrost and subsequently altering hydrologic regimes and vegetation distribution, physiognomy and productivity. Permafrost thaw and increased subsurface flow have been inferred from the chemistry of large rivers, but there is limited empirical evidence of the impacts to headwater streams. Here we demonstrate h
Authors
Joshua C. Koch, Ylva Sjöberg, Jonathan A. O'Donnell, Michael P. Carey, Pamela Sullivan, A. Terskaia