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
Marine mammal hotspots across the circumpolar Arctic Marine mammal hotspots across the circumpolar Arctic
Aim Identify hotspots and areas of high species richness for Arctic marine mammals.Location Circumpolar Arctic.Methods A 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...
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-Jorgensen, 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. Nordoy, Greg O’Corry-Crowe, Nils Oien, 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, Oystein 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 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...
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 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...
Authors
James V. Jones, Christopher G. Daniel
Topographic controls on ice flow and recession for Juneau Icefield (Alaska/British Columbia) 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...
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 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...
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 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...
Authors
Joshua C. Koch, Ylva Sjoberg, Jonathan A. O’Donnell, Michael P. Carey, Pamela Sullivan, A. Terskaia
Harmful algal blooms in the Alaskan Arctic: An emerging threat as oceans warm Harmful algal blooms in the Alaskan Arctic: An emerging threat as oceans warm
Harmful algal blooms (HABs) present an emerging threat to human and ecosystem health in the Alaskan Arctic. Two HAB toxins are of concern in the region: saxitoxins (STXs), a family of compounds produced by the dinoflagellate Alexandrium catenella, and domoic acid (DA), produced by multiple species in the diatom genus Pseudo-nitzschia. These potent neurotoxins cause paralytic and amnesic...
Authors
Donald Anderson, Evangeline Fachon, Katherine Hubbard, Kathi Lefebvre, Peigen Lin, Robert Pickart, Mindy Richlen, Gay Sheffield, Caroline R. Van Hemert
The role of satellite telemetry data in 21st century conservation of polar bears (Ursus maritimus) The role of satellite telemetry data in 21st century conservation of polar bears (Ursus maritimus)
Satellite telemetry (ST) has played a critical role in the management and conservation of polar bears (Ursus maritimus) over the last 50 years. ST data provide biological information relevant to subpopulation delineation, movements, habitat use, maternal denning, health, human-bear interactions, and accurate estimates of vital rates and abundance. Given that polar bears are distributed...
Authors
Kristin L. Laidre, George M. Durner, Nicholas J Lunn, Eric V. Regehr, Todd C. Atwood, Karyn D. Rode, Jon Aars, Heli Routti, Oystein Wiig, Markus Dyck, Evan S. Richardson, Stephen D Atkinson, Stanislav Belikov, Ian Stirling
Summer/fall diet and macronutrient assimilation in an Arctic predator Summer/fall diet and macronutrient assimilation in an Arctic predator
Free-ranging predator diet estimation is commonly achieved by applying molecular-based tracers because direct observation is not logistically feasible or robust. However, tracers typically do not represent all dietary macronutrients, which likely obscures resource use as prey proximate composition varies and tissue consumption can be specific. For example, polar bears (Ursus maritimus)
Authors
Craig A. Stricker, Karyn D. Rode, Brian D. Taras, Jeffrey F. Bromaghin, Lara Horstmann, Lori T. Quakenbush
Adaptation strategies and approaches for managing fire in a changing climate Adaptation strategies and approaches for managing fire in a changing climate
As the effects of climate change accumulate and intensify, resource managers juggle existing goals and new mandates to operationalize adaptation. Fire managers contend with the direct effects of climate change on resources in addition to climate-induced disruptions to fire regimes and subsequent ecosystem effects. In systems stressed by warming and drying, increased fire activity...
Authors
Martha Sample, Andrea E. Thode, Courtney Peterson, Michael Gallagher, William T. Flatley, Megan Friggens, Alexander Evans, Rachel A. Loehman, Shaula Hedwall, Leslie A. Brandt, Maria Janowiak, Christopher W. Swanston
First juvenile Chum Salmon confirms successful reproduction for Pacific salmon in the North American Arctic First juvenile Chum Salmon confirms successful reproduction for Pacific salmon in the North American Arctic
The distributional extent of Pacific salmon Oncorhynchus spp. in the North American Arctic is unresolved. While adult Pacific salmon have a recurring presence across the Alaskan North Slope and into the Canadian Arctic, it is uncertain if these fish are part of established Arctic populations, vagrants from outside sources reproducing unsuccessfully, or both. Here we present the first...
Authors
Karen M. Dunmall, Darcy G. McNicholl, Christian E. Zimmerman, Sara E. Gilk-Baumer, Sean E. Burril, Vanessa R. von Biela
Heterogeneous patterns of aged organic carbon export driven by hydrologic flow paths, soil texture, fire, and thaw in discontinuous permafrost headwaters Heterogeneous patterns of aged organic carbon export driven by hydrologic flow paths, soil texture, fire, and thaw in discontinuous permafrost headwaters
Climate change is thawing and potentially mobilizing vast quantities of organic carbon (OC) previously stored for millennia in permafrost soils of northern circumpolar landscapes. Climate-driven increases in fire and thermokarst may play a key role in OC mobilization by thawing permafrost and promoting transport of OC. Yet, the extent of OC mobilization and mechanisms controlling...
Authors
Joshua C. Koch, Matthew Bogard, David Butman, Kerri Finlay, Brian A. Ebel, Jason James, Sarah Ellen Johnston, M. Torre Jorgenson, Neal Pastick, Rob Spencer, Rob Striegl, Michelle A. Walvoord, Kimberly Wickland