Geochemical evidence for the origin of late Quaternary loess, Seward Peninsula, Alaska
Daniel R. Muhs, Jeffrey S. Pigati
2025, Arctic, Antarctic, and Alpine Research (57)
Loess is the most widespread surficial deposit in the state of Alaska. Although loess of last glacial age is common in mid-continental North America, records of last glacial loess in Alaska have been elusive. Here we report a record of last glacial loess on the Seward Peninsula,...
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...
Sea-level driven isolation of glacial plant refugia revealed by submerged lake sediment from the Bering Land Bridge and St. Matthew Island
Miriam C. Jones, Lesleigh Anderson, Beth Elaine Caissie, David J. Harning, Thomas A. Ager
2025, Arctic Antarctic and Alpine Research (57)
Bering Land Bridge (BLB) climate and vegetation during the Last Glacial Maximum (LGM) remains largely understudied, given challenges associated with collecting records from the submerged BLB. Previous records, confined to the margins of the modern land area and adjacent shelf, reveal conflicting interpretations of Beringian vegetation during...
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 J. 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...
Mechanisms influencing thermal refuges and territory occupancy by collared pikas during summer and winter
Lillian A. Harrison, Katherine S. Christie, Collette Brandt, Matthew Richard Falcy, Sophie L. Gilbert, Janet L. Rachlow
2025, Arctic, Antarctic, and Alpine Research (57)
Collared pikas (Ochotona collaris) are cold adapted alpine lagomorphs of western Canada and Alaska, USA, that are vulnerable to direct and indirect effects of climate change. However, how and to what extent such changes influence persistence for this species is not well understood, particularly at fine spatial...
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 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 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...
Mosquitos, forage and the future of Arctic caribou
Heather E. Johnson
2025, Newsletter
Climate change in the Arctic is altering summer forage and insect conditions for migratory caribou. Warmer, earlier summers can mean increased forage quantity, but reduced quality. At the same time, these conditions can trigger earlier, more intense periods of insect harassment. As HEATHER JOHNSON writes, these changes are associated with...
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...
Accounting for seasonal patterns in bird availability prevents biased population trend estimates with advancing spring phenology
Emily L. Weiser, James Johnson, Steven M. Matsuoka, Colleen M. Handel
2025, Ornithological Applications (127) 1-11
Advancing spring phenology has been observed around the world, including changes in the timing of breeding of birds. When singing rates are tied to breeding stage, the rate at which birds are available for detection by surveyors can also show seasonal patterns that may shift with spring phenology. As the...
Energetic value of Arctic forage-sized fish with implications for a nearshore seabird predator
Ashley E. Stanek, Brian D. Uher-Koch, Kenneth H. Dunton, Vanessa R. von Biela
2025, Marine Biology (172)
Arctic cod (Boreogadus saida, also called polar cod) are considered the single most important Arctic forage fish due to their high abundance and nutritional quality. Because Arctic cod are strongly ice associated and prefer colder waters, their frequency in coastal waters has declined with warming, decreasing availability to nearshore predators....
Paleoproterozoic vein graphite mineralization caused by decarbonation in the Ruby Range, Montana, USA
George N.D. Case, Jay Thompson, Sean P. Regan
2025, Conference Paper
Hydrothermal graphite veins are a possible source for modern battery materials and require better understanding of their carbon source(s) and absolute timing to develop mapable criteria for exploration models. We present new observations of graphite vein and alteration paragenesis and U-Pb LA-ICP-MS titanite age data from the Ruby prospect, Montana,...
Assessing United States gallium and germanium resources in basin-hosted deposits – The good and bad
Garth E. Graham, Erik Roger Tharalson
2025, Conference Paper
Basin-hosted Zn-Pb deposits, including MVT and clastic-dominated (CD or “Sedex”) Zn-Pb deposits are major sources of Zn and Pb, as well as other critical elements. We examined available whole rock and sphalerite chemistry data to understand the apparent variation of Ga and Ge among major current and historical districts of...
Evidence for offset of Cretaceous plutons by the Tintina fault in eastern Alaska: Implications for regional metallogeny
Douglas C. Kreiner, Erin Todd, James V. Jones III, Christopher S. Holm-Denoma, Laura Pianowski, Paul O’Sullivan
2025, Conference Paper
Cretaceous magmatism in eastern interior Alaska is voluminous, but temporally and spatially diverse – suggestive of varying sources and drivers. More than 150 new U-Pb zircon and more than 500 geochemical analyses of Cretaceous plutonic units allow for the grouping of distinct plutonic suites. Magmatism was continuous from 120-66 Ma...
Synergy between geology and geophysics in graphite mineral resource assessment
Patricia Grace Macqueen, George N.D. Case, Paul A. Bedrosian, Jane M. Hammarstrom, Susan M. Karl, Graham W. Lederer, Elizabeth M. Bollen, John Whitmore, Dane VanDervoort, Abraham M. Emond, Logan Fusso, Philip J. Brown, Gregory J. Walsh, Keith A. Labay, Martha Stokes, Andrew Arnold Stewart
2025, Conference Paper
Graphite is designated as a critical mineral by the U.S. Government due to its essential role in modern technology and its vulnerability to supply chain disruption. To evaluate domestic graphite resources, the U.S. Geological Survey (USGS) conducted two airborne electromagnetic (AEM) surveys as part of the Earth Mapping Resources Initiative...
From critical minerals to food security, the benefits of data collaboration
Steph G. Hawkins, K Waltenberg, Catherine A. Stuart, Evgeniy Bastrakov, George N.D. Case, Jagoda Crawford, Lian Flick, Geoff Fraser, Christoph Gerber, Garth E. Graham, Kristin Guerin, Albert H. Hofstra, Cath Hughes, David L. Huston, Chris J.M. Lawley, Nina Welti, Bronwen Wang, Aaron Sedgmen, Vladimir A. Lisistin, Paul Abhijit, Tim Stobaus, Axel Suckow
2025, Conference Paper
The volume of data in the public geoscience sphere is rapidly and continually expanding. At Geoscience Australia (GA) we saw an over 500% increase in data points within our relational databases between 2018 and 2024, over the life of the Exploring for the Future (EFTF) program. With the Resourcing Australia’s Prosperity...
Speleothem evidence for Late Miocene extreme Arctic amplification – An analogue for near-future anthropogenic climate change?
Stuart Umbo, Franziska Lechleitner, Thomas Opel, Sevasti Modestou, Tobias Braun, Anton Vaks, Gideon Henderson, Pete Scott, Alexander Osintzev, Alexander Kononov, Irina Adrian, Yuri Dublyansky, Alena Maria Giesche, Sebastian F.M. Breitenbach
2025, Climate of the Past (21) 1533-1551
The Miocene provides an excellent climatic analogue for near-future runaway anthropogenic warming, with atmospheric CO2 concentrations and global average temperatures similar to those projected for the coming century under extreme-emissions scenarios. However, the magnitude of Miocene Arctic warming remains unclear due to the scarcity of reliable proxy data. Here we use...
Avak Creek oil occurrence, North Slope, Alaska: Newly discovered oil seep on Native lands, near village of Utqiagvik
Palma J. Botterell, David W Houseknecht, Jody Brae Wycech, J. Mike Moldowan, Paul G. Lillis, Rebecca A. Smith, Kimberley Maher
2025, Conference Paper
An unknown occurrence of oil was detected near Avak Creek on Native lands on the North Slope of Alaska. Determining the source of oil was imperative for allowing stakeholders (Federal, State, and local government agencies and the landowner, an Alaska Native corporation) to make timely and informed decisions and mount...
Estimated average annualized tsunami losses for the United States
Anne Sheehan, Casey Zuzak, Nathan J. Wood, Doug Bausch, Cadie Goulette Yeager, Alice McDougall
2025, Report
Tsunami hazards are substantial threats to coastal communities across the United States (U.S.) and its territories. U.S. states and territories collaborate through the National Tsunami Hazard Mitigation Program (NTHMP) to develop their own tsunami-hazard information for outreach and evacuation planning. An effort to curate this tsunami-hazard information to support comprehensive...
U.S. Geological Survey science strategy to address white-nose syndrome and bat health in 2025–2029
M. Camille Hopkins, Amy E. George, Rebecca M. McCaffery
2025, Circular 1560
Since its discovery in 2006, the fungal disease known as white-nose syndrome (WNS) has killed millions of bats. Of the 47 bat species native to the conterminous United States, Alaska, Hawaii, and Canada, 12 have been affected by WNS, including 3 endangered species and 1 proposed endangered species. WNS has also been detected in...
