An energetic tradeoff best explains parturition timing in grizzly bears
C. M. Costello, L. L. Roberts, D. D. Bjornlie, M. D. Cameron, J. G. Clapp, Mark Haroldson, G. V. Hilderbrand, K. Joly, W. Kasworm, J. M. Nicholson, T. Radandt, M. S. Sorum, J. E. Teisberg, Frank T. van Manen, M. A. Vinks
2026, Ecology and Evolution (16)
Timing of grizzly bear (Ursus arctos) parturition during hibernation has been explained by ancestral traits (delayed implantation, altricial young, obligate maternal denning), but the ultimate driver underlying precise timing has not been fully explored. Capitalizing on an observed latitudinal increase in denning duration among four populations in interior North America,...
Tectonic implications of transitional melting regimes from petrological, geochronological, and compositional characterization of the ophiolitic Seventymile terrane, Alaska, USA
Erin Todd, Jonathan Saul Caine, Michael Bizimis, Andrew R.C. Kylander-Clark, Robert Reece Hammond, Alicja Wypych
2026, Geosphere
New geochemical, U-Pb geochronology, and Sr-Nd-Hf isotope data provide evidence for the tectonic evolution of the Seventymile terrane in interior Alaska, USA. Ultramafic and mafic rocks of the Seventymile terrane are thought to represent components of a dismembered ophiolite and provide unique constraints on regional terrane evolution and accretion. The...
Toward an efficient framework for remote sensing of river bathymetry: Comparing sensors and algorithms on an inaccessible proglacial river in Alaska
Carl J. Legleiter, Christina M. Leonard, Paul A. Burger, Addison G. Pletcher, Paul J. Kinzel
2026, Geomorphology (495)
Remote sensing can provide reliable information on river depths and this approach might be particularly valuable in areas that are difficult to survey via conventional field methods. In this study, we assessed the potential to map the bathymetry of an inaccessible proglacial river in Alaska from both aerial orthophotos and...
Cumulative effects analysis to inform public land management in the United States: Key characteristics and legal challenges
Tait K. Rutherford, Tim O. Hammond, Alison C. Foster, Megan A. Gilbert, Travis S. Haby, Richard J. Lehrter, Jennifer K. Meineke, Ella M. Samuel, Sarah K. Carter
2026, Environmental Impact Assessment Review (117)
Considering potential cumulative effects of proposed actions is fundamental to environmental impact analysis. However, cumulative effects analyses historically are not robust, especially for site-specific decisions. We sought to identify opportunities to strengthen cumulative effects analysis in a large United States public land management agency, the Bureau of Land Management (BLM)....
U.S. Geological Survey—Department of the Interior, Region 11, Alaska—2023–24 biennial science report
Elizabeth M. Powers, Dee M. Williams, editor(s)
2025, Circular 1554
IntroductionU.S. Geological Survey (USGS) Mission—The USGS national mission is to monitor, analyze, and predict the current and evolving dynamics of complex human and natural Earth-system interactions and to deliver actionable information at scales and timeframes relevant to decision makers. Consistent with the national mission, the USGS in Alaska provides timely...
Multi-temporal surface water mapping with high-resolution elevation and image data through weakly supervised deep learning
Larry Stanislawski, Rongjun Qin, Jung-Kuan Liu, Ethan J. Shavers, Shaowen Wang, Nattapon Jaroenchai, Philip T. Thiem
2025, Conference Paper, Abstracts of the International Cartographic Association
Monitoring the extent of surface water features (hydrography), accurately storing them in databases, and representing them on topographic maps are essential for various applications such as navigation and policy-making for legislative boundaries and permitting. In this context, hydrographic data includes features that generally have water present or image data showing...
A time-space model of graphite mineral systems
George N.D. Case
2025, Mineralium Deposita
Increasing demand for graphite in energy storage systems warrants review of graphite ore genesis in a mineral systems framework. Orogenic graphite encompasses the metamorphic and orogenic mineral systems that produce flake graphite and hydrothermal vein (lump and chip) graphite deposits, respectively. A common feature of orogenic graphite deposits is an...
Toward co-designed Earth System Models: Reflecting end-user priorities in local applications from a modeler's perspective
Yifan Cheng, Nicole M. Herman-Mercer, Andrew J. Newman, Keith Musselman, Cleo Woelfle-Hazard, Dylan Blaskey, Cassandra M. Brooks, Tvetene Carlson, Joshua C. Koch, Monica Morrison, Edda A. Mutter, Daniel Sarna-Wojcicki, Peyton Thomas, Jenessa Tlen, Ryan C. Toohey
2025, AGU Advances (6)
Earth System Models (ESM) are crucial for quantifying climate impacts across Earth's interconnected systems and supporting science-based adaptation and mitigation. However, not including end-users, especially decision-makers representing communities vulnerable to climate change, can limit model utility, increase epistemic risks, and lead to information misuse in decision-making. While the...
Power source, data retrieval method, and attachment type affect success of dorsally mounted tracking tag deployments in 37 species of shorebirds
Emily L. Weiser, Richard Lanctot, Daniel R. Ruthrauff, Sarah T. Saalfeld, Lee Tibbitts, José Abad-Gómez, Joaquin Aldabe, Juliana Bose de Almeida, José A. Alves, Guy Anderson, Phil F. Battley, Heinrich Belting, Joël Bêty, Kristin Bianchini, Mary Anne Bishop, Roeland A. Bom, Katharine Bowgen, Glen S. Brown, Stephen C. Brown, Leandro Bugoni, Niall Burton, David R. Bybee, Camilo Carneiro, Gabriel Castresana, Ying-Chi Chan, Chi-Yeung Choi, Katherine Christie, Nigel A. Clark, Jesse R. Conklin, Medardo Cruz-López, Stephen J. Dinsmore, Steve Dodd, David C. Douglas, Luke Eberhart-Hertel, Willow B. English, Harry Ewing, Fernando A. Faria, Samantha E. Franks, Richard A. Fuller, Robert E. Gill Jr., Marie-Andrée Giroux, Cheri L Gratto-Trevor, David Green, Rhys E. Green, Ros Green, Tómas Gunnarsson, Jorge S. Gutiérrez, Autumn-Lynn Harrison, C. Alex Hartman, Chris J. Hassell, Sarah Hoepfner, Jos C. E. W. Hooijmeijer, James Johnson, Oscar W. Johnson, Bart Kempenaers, Marcel Klaassen, Eva Kok, Johannes Krietsch, Clemens Küpper, Andy Kwarteng, Eunbi Kwon, Jean-Francois Lamarre, Christopher Latty, Nicolas Lecomte, A.H. Loonstra, Zhijun Ma, Lucas Mander, Christopher Marlow, Peter P. Marra, Jose A. Masero, Laura Anne McDuffie, Rebecca L McGuire, Johannes Melter, David S. Melville, Verónica Méndez, Tyler Michels, Christy Morrissey, Tong Mu, David Newstead, Gary W. Page, Allison K. Pierce, Theunis Piersma, Márcio Repenning, Brian H. Robinson, Afonso Rocha, Danny I. Rogers, Amy L. Scarpignato, Shiloh Schulte, Emily Scragg, Nathan R. Senner, Paul Smith, Audrey R. Taylor, Rachel C. Taylor, Böðvar Þórisson, Mihai Valcu, Mo A. Verhoeven, Lena Ware, Nils Warnock, Michael Weber, Lucy J. Wright, Michael B. Wunder
2025, Journal of Avian Biology (2025)
Animal-borne trackers are commonly used to study bird movements, including in long-distance migrants such as shorebirds. Selecting a tracker and attachment method can be daunting, and methodological advancements often have been made by trial and error and conveyed by word of mouth. We synthesized tracking outcomes across...
River ice controls permafrost bank erosion across an Arctic delta
J Arcuri, Irina Overeem, Marisa Repasch, R. S. Anderson, S. P. Anderson, Joshua C. Koch, Frank Urban
2025, Earth Surface Processes and Landforms (50)
Bank erosion in Arctic rivers helps shape channel geometry, mobilizes carbon from permafrost and influences sediment delivery to the Arctic Ocean. On Alaska's Arctic coastal plain, rivers begin flowing during snowmelt in late spring while extensive river ice persists in channels, such that hydraulics are altered and water is kept...
The effects of carnivory and herbivory on the energy balance of Arctic grizzly bears
Anthony M. Pagano, Karyn D. Rode, Kerry L. Nicholson, William B. Leacock, Craig A. Stricker, Charles T. Robbins
2025, Oecologia (208)
Omnivores often face tradeoffs between selecting for spatially dispersed energy-dense vertebrate prey versus densely distributed herbivorous resources that have limited energetic value per unit intake. Arctic grizzly bears (Ursus arctos) are large omnivores within a resource-limited ecosystem that are known to exhibit smaller body masses and occur at lower densities...
Comparisons of shoreline positions from satellite-derived and traditional field- and remote-sensing techniques
Andrea C. O'Neill, Sharon F. Batiste, Daniel D. Buscombe, Joseph Burgess, Kara S. Doran, Ann E. Gibbs, Rachel E. Henderson, Julia L. Heslin, Catherine N. Janda, Mark A. Lundine, Joseph F. Terrano, Jonathan A. Warrick, Kathryn M. Weber
2025, Open-File Report 2025-1054
Satellite-derived shorelines (SDS) have the potential to help researchers answer critical coastal science questions and support work to predict coastal change by filling in the spatial and temporal gaps present in current field-based and remote-sensing data collection methods. The U.S. Geological Survey conducted comparison analyses of traditionally sourced shorelines and...
The 1912 Ms 7.2 earthquake in the Denali region of central Alaska
Carl Tape, Marco Aquino-Lopez, Sean Bemis, Peter J. Haeussler, Jessalyn Ginnaty
2025, Bulletin of the Seismological Society of America
The 2002 Mw 7.9 earthquake in central Alaska ruptured 340 km on three faults—Susitna Glacier thrust fault, Denali fault, Totschunda fault—crossing both the Richardson Highway and the Alaska Pipeline. Its occurrence prompted renewed interest in historical large earthquakes that possibly originated on the Denali fault. One of these earthquakes was a Ms 7.2...
Observational, virological, and serological data provide insights into an outbreak of highly pathogenic avian influenza among wild birds on the Yukon-Kuskokwim Delta, Alaska in 2022
Bryan Daniels, Erik E. Osnas, Megan Boldenow, Robert Gerlach, Christina Ahlstrom, Sarah Coburn, Michael J. Brook, Michael Brubaker, Julian Fischer, David N. Koons, Angela Matz, Marin Murphy, Daniel Rizzolo, Laura Celeste Scott, David R. Sinnett, Jordan M. Thompson, Juliana Lenoch, Mia Kim Torchetti, David E. Stallknecht, Rebecca L. Poulson, Andrew M. Ramey
2025, Journal of Wildlife Diseases (61) 1010-1027
In 2021–22, clade 2.3.4.4b highly pathogenic avian influenza (HPAI) viruses were introduced by wild birds into North America, leading to geographically widespread disease. In response to HPAI outbreaks throughout late 2021 and early 2022, we recorded observations of sick and dead birds, estimated abundance of carcasses, collected swab and sera...
Reply to the discussion by Pilfold “Polar bear mass change confirms hyperphagia follows ringed seal whelping”
Anthony M. Pagano, Stephen N. Atkinson, Louise C. Archer
2025, Arctic Science (11) 1-3
The spring is a critical period when polar bears (Ursus maritimus Phipps, 1774) are thought to have peak access to seals and acquire the majority of their annual energy requirements during a period of hyperphagia. Pagano et al. (Pagano A.M., Atkinson S.N., and Archer L.C. 2025. Arctic Science.11:1-14. doi:10.1139/as-2024-0051) examined the...
Mount Spurr volcano, August 18, 1992: The eruption heard around Alaska
Alexandra M. Iezzi, John Power
2025, Bulletin of Volcanology (87)
The August 18, 1992, eruption of Mount Spurr volcano, Alaska, produced an impressive Vulcanian to Subplinian eruption column reaching up to 40 km above sea level that blanketed the nearby city of Anchorage with ash. At the time of the eruption, the Alaska Volcano Observatory received reports of audible sound hundreds...
Near real-time indicators of burn severity in the western U.S. from active fire tracking
Elijah Orland, Tempest McCabe, Yang Chen, Rebecca C. Scholten, Zeb Becker, Rachel A. Loehman, James T. Randerson, Shane R. Coffield, Tianjia Liu, Alexey N. Shiklomanov, Kurtis Nelson, Birgit Peterson, Melanie B. Follette-Cook, Douglas C. Morton
2025, Fire Ecology (21)
BackgroundTimely information on wildfire burn severity is critical to assess and mitigate potential post-fire impacts on soils, vegetation, and hillslope stability. Tracking individual fire spread and intensity using satellite active fire data provides a pathway to near real-time (NRT) information. Here, we generated a large database (n = 2177) of wildfire events...
Host responses and viral traits interact to shape the impacts of climate warming on highly pathogenic avian influenza in migratory waterfowl
Claire Stewart Teitelbaum, Michael L. Casazza, Cory T. Overton, Elliott Matchett, Diann Prosser
2025, PLOS Computational Biology. (21)
Emerging infectious diseases pose threats to wildlife populations, as exemplified by recent outbreaks of avian influenza viruses in wild birds. Climate change can affect infection dynamics in wildlife through direct effects on pathogens (e.g., environmental decay rates) and changes to host ecology, including shifting migration patterns. Here, we adapt an...
Case study of deep learning image segmentation for the purposes of rapid 2D petrographic analysis in volcanic rocks
Brenna A. Halverson, Matthew W. Loewen, Hannah R. Dietterich, Alan Whittington
2025, Volcanica (8) 427-443
Automation using deep learning methods is a useful alternative to manual methods of petrographic segmentation, but often requires user familiarity with coding and/or algorithms. We examine the DragonflyTM program's deep learning tools for application by users with a variety of skill levels as a method for petrographic image segmentation. An...
Monitoring Pacific walrus coastal haulouts by satellite to estimate herd abundance and distribution
Anthony S. Fischbach, Rebecca L. Taylor, David C. Douglas
2025, Wildlife Society Bulletin (49)
The Pacific walrus (Odobenus rosmarus divergens) has a single, panmictic stock that ranges across the Bering and Chukchi Seas. However, its seasonal distribution is incompletely described, particularly in autumn when herds gather on shore, and abundance is of interest to management entities. We monitored walrus herds using satellite imagery on...
Combining scanning electron microscopy, X-ray diffraction, and X-ray fluorescence to characterize shear zones at the Pogo gold deposit, Alaska
Katharina I Pfaff, Filip Kasprowicz, Jonathan Saul Caine, William Benzel, Heather A. Lowers
2025, Conference Paper
This study employs a multi-method analytical approach to characterize the mineralogical, geochemical, and textural properties of fault rocks from the Pogo gold mine in the Yukon-Tanana Upland, central Alaska. Specifically, we examine cataclasites, to document the structural and geochemical evolution of shear zones and their associations with gold mineralization. To...
Deformation mechanisms in quartz veins and shear zones elucidate the origin of gold mineralization at Pogo, Alaska
Jonathan Saul Caine, Douglas C. Kreiner, Heather A. Lowers
2025, Conference Paper
Pogo is a quartz vein hosted, ca. 8 Moz gold deposit. Although it has similarities to orogenic and magmatic-hydrothermal deposits, its origin remains enigmatic. Observations from surface exposures, underground workings, and drill core provide new constraints on quartz vein origins with implications for mineralization. Abundant, largely barren metamorphic segregation quartz...
User’s guide for the National Hydrography Dataset Plus High Resolution (NHDPlus HR)
Richard B. Moore, Lucinda D. McKay, Alan H. Rea, Timothy R. Bondelid, Curtis V. Price, Thomas G. Dewald, Laura Hayes
2025, Scientific Investigations Report 2025-5031
The National Hydrography Dataset Plus High Resolution (NHDPlus HR) is a scalable hydrologic geospatial fabric or framework, built from (1) the High Resolution (1:24,000-scale or better) National Hydrography Dataset (NHD), (2) nationally complete Watershed Boundary Dataset (WBD), and (3) 1/3-arc-second 3D Elevation Program (3DEP) digital elevation model (DEM) data (at...
Estimated average annualized losses from potential building damage and fatalities due to earthquake-generated tsunamis in the United States
Nathan J. Wood, Anne Sheehan, Douglas Bausch, Cadie Goulette Yeager, Casey Zuzak, Jennifer Sims, Ashley Hoke
2025, International Journal of Disaster Risk Reduction (130)
Earthquake-generated tsunamis represent substantial economic threats to states and territories in the United States (U.S.), but we are unaware of any effort to quantify potential impacts at the national level. This gap is partially due to the lack of nationally consistent data on tsunamigenic sources and associated return periods. This...
Bears avoid residential neighborhoods in response to the experimental reduction of anthropogenic attractants
Cassandre C. Venumière-Lefebvre, Heather E. Johnson, Stewart W. Breck, Mathew W. Alldredge, Kevin R. Crooks
2025, Frontiers in Ecology and Evolution (13)
Introduction: Urbanization is an extreme form of land use alteration, with human development driving changes in the distribution of resources available to wildlife. Some large carnivores have learned to exploit anthropogenic food resources in urban development, resulting in human-carnivore conflict that can have detrimental impacts to people and carnivores, as exemplified...
