Apatite geo-thermochronology and geochemistry constrain Oligocene-Miocene growth and geodynamics of the northeastern Tibetan Plateau
Chao Guo, Zhiyong Zhang, Richard O. Lease, Marco Malusa, David Chew, Haijian Lu, Lin Wu, Dunfeng Xiang, Nan Wang, Bernhard Grasemann, Wenjiao Xiao
2025, Geophysical Research Letters (52)
Understanding the geodynamics of plateau evolution requires examining the spatial and temporal aspects of mountain building in the northeastern Tibetan Plateau, which are still under debate. Here we integrate apatite geo-thermochronological and geochemical data from the Oligocene-Miocene succession of the Xunhua Basin to elucidate the evolution of the regional topography....
Developing a probabilistic tsunami hazard assessment framework for Pacific sources: USGS Powell Center meeting summary
Jason R. Patton, Stephanie L Ross, Marie C. Eble, Christodoulos Kyriakopoulos, Patrick J. Lynett, DmitriyJ. Nicolsky, Kenneth Ryan, Hong Kie Thio, Rick I. Wilson, Baoning Wu
2025, Environmental & Engineering Geoscience (31) 67-76
Multi-organizational principal investigators formed a U.S. Geological Survey (USGS) Powell Center Working Group (WG), Tsunami Source Standardization for Hazards Mitigation in the United States, to develop a comprehensive series of sources capable of generating tsunamis that could impact U.S. state and territory coastal areas using probabilistic tsunami hazard analysis (PTHA)....
An unexplained tsunami: Was there megathrust slip during the 2020 Mw7.6 Sand Point, Alaska, earthquake?
Sean R. Santellanes, Dara Elyse Goldberg, Pablo Koch, Diego Melgar, William L. Yeck, Brendan W. Crowell, Jiun-Ting Lin
2025, Seismica (4) 1-13
On October 19, 2020, the Mw7.6 Sand Point earthquake struck south of the Shumagin Islands in Alaska. Moment tensors indicate the earthquake was primarily strike-slip, yet the event produced an enigmatic tsunami that was larger and more widespread than expected for an earthquake of that magnitude and mechanism. Using a...
A fire deficit persists across diverse North American forests despite recent increases in area burned
Sean Parks, Chris Guiterman, Ellis Q. Margolis, Maggie Lonergan, Ellen Whitman, John T. Abatzoglou, Donald A. Falk, James B. Johnston , Lori D. Daniels, Charles W. Lafon, Rachel A. Loehman, Kurt F. Kipfmueller, Cameron E. Naficy, Marc-Andre Parisien, Jeanne Portier, Michael C. Stambaugh, A. Park Williams, Andreas Paul Wion, Larissa Yocom
2025, Nature Communications (16)
Rapid increases in wildfire area burned across North American forests pose novel challenges for managers and society. Increasing area burned raises questions about whether, and to what degree, contemporary fire regimes (1984–2022) are still departed from historical fire regimes (pre-1880). We use the North American tree-ring fire-scar network (NAFSN), a...
Bait trapping of waterfowl increases the environmental contamination of avian influenza virus (AIV)
Cassandra Andrew, Landon McPhee, Kevin Kuchinski, Jordan Wight, Ishraq Rahman, Sarah Mansour, Gabrielle Angelo Cortez, Marzieh Kalhor, Ethan Kenmuir, Natalie Prystajecky, Kathryn Hargan, Andrew Lang, James Leafloor, Catherine Soos, Andrew M. Ramey, Chelsea Himsworth
2025, Journal of Wildlife Management (89)
Highly pathogenic avian influenza virus (HPAIV) H5Nx clade 2.3.4.4b has circulated in North America since late 2021, resulting in higher rates of morbidity and mortality in wild birds than observed in this region before. The objective of this study was to determine whether baiting, which is widely conducted in Canada...
2022 Volcanic activity in Alaska and the Northern Mariana Islands—Summary of events and response of the Alaska Volcano Observatory
Tim R. Orr, Hannah R. Dietterich, Ronni Grapenthin, Matthew M. Haney, Matthew W. Loewen, Pablo Saunders-Shultz, Darren Tan, Christopher F. Waythomas, Aaron G. Wech
2025, Scientific Investigations Report 2024-5108
In 2022, the Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at 11 volcanic centers in Alaska and in the Northern Mariana Islands. Eruptive activity in Alaska consisted of repeated small, ash-producing, phreatomagmatic explosions from Mount Young on Semisopochnoi Island; the...
Forecasting sea otter recolonization: Insights from isotopic analysis of modern and zooarchaeological populations
Emma A. Elliott Smith, Madonna L. Moss, Hannah P. Wellman, Verena A. Gill, Daniel Monson, Seth D. Newsome
2025, Proceedings of the Royal Society B, Biological Sciences (292)
Retrospective datasets offer essential context for conservation by revealing species’ ecological roles before industrial-era human impacts. We analysed isotopic compositions of pre-industrial and modern sea otters (Enhydra lutris) to reconstruct pre-extirpation ecology and offer insights for management. Our study focuses on southeast Alaska (SEAK), where sea otters are recolonizing, and...
The importance of method selection when estimating diet composition with quantitative fatty acid signature analysis
Jeffrey F. Bromaghin, Todd C. Atwood, Karyn D. Rode
2025, PLoS ONE (20)
Quantitative fatty acid signature analysis (QFASA) is a common method of estimating the composition of prey species in the diets of consumers from polar and temperate ecosystems in which lipids are an important source of energy. A key characteristic of QFASA is that the large number of fatty acids that...
Towards mobile wind measurements using joust configured ultrasonic anemometer for applications in gas flux quantification
Derek Hollenbeck, Colin W. Edgar, Eugenie Euskirchen, Kristen L. Manies
2025, Drones (9)
Small uncrewed aerial systems (sUASs) can be used to quantify emissions of greenhouse and other gases, providing flexibility in quantifying these emissions from a multitude of sources, including oil and gas infrastructure, volcano plumes, wildfire emissions, and natural sources. However, sUAS-based emission estimates are sensitive to the accuracy of wind...
Variation in energetic balance among free-ranging polar bears during the spring mating and foraging season
Anthony M. Pagano, Stephen N. Atkinson, Louise C. Archer
2025, Arctic Science (11) 1-14
Large carnivores are capable of consuming substantial biomasses that can significantly alter their body mass and condition over short periods. Here we examine the intra-seasonal variation of polar bear (Ursus maritimus Phipps, 1774) body mass, energy intake, and condition in the spring from two subpopulations. We evaluate the biological and temporal...
Slow slip detectability in seafloor pressure records offshore Alaska
Erik Fredrickson, Joan S. Gomberg, William Wilcock, Susan Hautala, Albert Hermann, H. Paul Johnson
2025, Journal of Geophysical Research (128)
In subduction zones worldwide, seafloor pressure data are used to observe tectonic deformation, particularly from megathrust earthquakes and slow slip events (SSEs). However, such measurements are also sensitive to oceanographic circulation-generated pressures over a range of frequencies that conflate with tectonic signals of interest. Using seafloor pressure and temperature data...
Water supply in the conterminous United States, Alaska, Hawaii, and Puerto Rico, water years 2010–20
Galen Gorski, Edward G. Stets, Martha A. Scholl, James R. Degnan, John R. Mullaney, Amy E. Galanter, Anthony J. Martinez, Julie Padilla, Jacob H. LaFontaine, Hayley R. Corson-Dosch, Allen Shapiro
2025, Professional Paper 1894-B
We present an assessment of water supply across the conterminous United States (CONUS), Alaska, Hawaii, and Puerto Rico covering water years 2010–20. Our analysis drew on two national hydrologic models, the National Hydrologic Model Precipitation-Runoff Modeling System and the Weather Research and Forecasting model hydrologic modeling system. Both models produced...
Chemostratigraphy of the Cretaceous Hue Shale in Arctic Alaska: Exploring paleoceanographic controls on trace element enrichment, organic matter accumulation, and source-rock evolution
Palma J. Botterell, Margaret M. Sanders, David W. Houseknecht, Richard O. Lease, William A. Rouse, Katherine J. Whidden, Julie A. Dumoulin, Rebecca A. Smith, Christina A. DeVera, Brett J. Valentine
2025, Applied Geochemistry (180)
We document chemostratigraphy in an outcrop of late Albian to early Campanian (∼103–82 Ma) marine source rocks to better understand paleoenvironmental controls on trace element (TE) enrichment and organic matter accumulation in the distal Colville foreland basin of Arctic Alaska and how those drivers are linked to arc volcanism and successions...
History of terrestrial ecosystem development in southern Alexander Archipelago, Alaska since the onset of deglaciation
Thomas A. Ager, James F Baichtal
E. J. Dixon, editor(s)
2025, Book chapter, Shuká Káa Cave, southeast Alaska: Archeology, ecology, and community (Aurora volume IX)
This chapter focuses on reconstructing the history of vegetation development in southern Alexander Archipelago (AA) of southeast Alaska during and after deglaciation up to the present day. It also summarizes key findings from recent paleoceanographic research in the Gulf of Alaska to provide a detailed, well-dated record of late Quaternary...
Site-level connectivity identified from multiple sources of movement data to inform conservation of a migratory bird
M. Beal, J. Nightingale, J.R. Belo, C. Batey, H. Belting, P. Bocher, M. Burgess, T.B. Craft, N. Crockford, P. Delaporte, L. Donaldson, G. Gelinaud, J.A. Gill, T.G. Gunnarsson, B. J. Morrison, J.S. Gutierrez, J. Hooijmeijer, R.A. Howison, P. Hunke, L. Jomat, H. Lemke, J. P. Ludwig, F.A. Majoor, C. Marlow, J.A. Masero, J. Melter, I. Nicholson, M. Parejo, B. O'Mahony, E. Pasanen, J. Pessa, T. Piersma, A.D. Rocha, F. Robin, M. Roodbergen, P. Rousseau, V. Salewski, L. Schmidt, J. Smart, A. Staneva, T. Lee Tibbitts, S. Timonen, J.A. Alves, M.P. Dias
2025, Journal of Applied Ecology (62) 303-316
Migratory birds depend on a suite of sites across their annual cycles, making them vulnerable to a wide variety of anthropogenic pressures. Current area-based conservation measures have been found inadequate to safeguard migratory birds, in part due to a lack of consideration for the connectivity between sites mediated by...
Generalized Bancroft algorithm for locating earthquakes with P- and S-wave arrival times
Matthew M. Haney
2025, Bulletin of the Seismological Society of America (115) 367-378
Because of similarities between locating an earthquake with seismic stations and locating a Global Positioning System (GPS) receiver from satellites, the Bancroft algorithm developed for GPS processing can be used to locate earthquakes. Such an approach to earthquake location differs from the conventional method of choosing an initial or trial...
Invited perspectives: Integrating hydrologic information into the next generation of landslide early warning systems
Benjamin B. Mirus, Thom Bogaard, Roberto Greco, Manfred Stähli
2025, Natural Hazards and Earth Systems Sciences (NHESS) (25) 169-182
Although rainfall-triggered landslides are initiated by subsurface hydro-mechanical processes related to the loading, weakening, and eventual failure of slope materials, most landslide early warning systems (LEWS) have relied solely on rainfall event information. In previous decades, several studies demonstrated the value of integrating proxies for subsurface hydrologic information to improve...
Leveraging airborne imaging spectroscopy and multispectral satellite imagery to map glacial sediment plumes in Kachemak Bay, Alaska
Lea Hartl, Carl Schmitt, Martin Stuefer, J. Jenckes, Benjamin Patrick Page, Christopher J. Crawford, Gail L. Schmidt, R. Yang, R. Hock
2025, Journal of Hydrology: Regional Studies (57)
Study RegionKachemak Bay is a fjord-type estuary in the northern Gulf of Alaska. Water quality and habitat characteristics are strongly influenced by freshwater and sediment input from multiple glacierized catchments.Study FocusWe present a new method combining imaging spectroscopy from an...
Sex differences in migration routes and non-breeding areas of a declining shorebird
Ann E. McKellar, Cheri L Gratto-Trevor, T. Lee Tibbitts
2025, Avian Conservation and Ecology (20)
Migratory birds face different threats and pressures across their annual cycle, and understanding the impact of these factors on individuals is critical to the conservation of avian populations. Individuals from the same breeding population may share the same non-breeding areas, and thus experience similar conditions, or they may travel to...
Evaluating effects of tracking device attachment methods on Black Oystercatchers Haematopus bachmani
Cole Rankin, Lena Ware, Brian H. Robinson, Daniel Esler, Heather Coletti, Mark Maftei, J Mark Hipfner, David Green
2025, Wader Study (131) 204-213
Advances in tracking technology are greatly improving our understanding of many aspects of avian ecology. However, the diversity of tracking devices and attachment methods necessitates better evaluation of how they affect particular taxa. We evaluated effects of tracking devices mounted on leg bands or attached using leg-loop harnesses on resighting...
Glass laser ablation-inductively coupled plasma-mass spectrometry analysis methods, precision, and accuracy data for tephra studies in Alaska
Jordan Edward Lubbers, Matthew W. Loewen
2025, Alaska Division of Geological & Geophysical Surveys Techniques and Methods 1
This publication reports the analytical conditions, standard reference material (SRM) results, and preferred post-processing methodologies for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) measurements supporting tephra studies in Alaska between 2018 and 2024. We evaluate the long-term accuracy and precision of our methodologies by comparing our calculated SRM concentrations...
Mountain sentinels in a changing world: Review and conservation implications of weather and climate effects on mountain goats (Oreamnos americanus)
Kevin White, Becky Cadsand, Steeve D. Cote, Tabitha A. Graves, Sandra Hamel, Richard B. Harris, Forest Hayes, Eran Hood, Kevin Hurley, Tyler Jessen, Bill Jex, Erich H. Peitzsch, Wesley Sarmento, Helen M. Schwantje, Joel Berger
2025, Global Ecology and Conservation (57)
Climate change is occurring at an accelerated rate in high-elevation alpine and mountain ecosystems. Cold-adapted, mountain species are at risk due to forecasted change and knowledge is needed to respond to current and future conservation challenges. Mountain goats (Oreamnos americanus) are an iconic species of North American mountain cultures and...
Assessing the sustainability of Pacific walrus harvest in a changing environment
Devin L. Johnson, Joseph Michael Eisaguirre, Rebecca L. Taylor, Erik M. Andersen, Joel L. Garlich-Miller
2025, Journal of Wildlife Management (89)
Harvest sustainability is a primary goal of wildlife management and conservation, and in a changing world, it is increasingly important to consider environmental drivers of population dynamics alongside harvest in cohesive management plans. This is particularly pertinent for harvested species that acutely experience effects of climate change. The Pacific walrus...
International data gaps at the Center for Engineering Strong Motion Data
Han Shao, Jeff Brody, Lisa Sue Schleicher, Kristin Marano, Jamison Haase Steidl, Eric M. Thompson, Mike Hearne, James Luke Blair
2025, Conference Paper
The Center for Engineering Strong Motion Data (CESMD) is utilized by seismologists, engineers, and disaster management professionals in the US and has historically achieved and distributed waveforms from across the globe for significant earthquakes. The increased access to the waveforms via Web API (Application Programming Interface) offers a unique opportunity...
Oblique contraction along the fastest ocean-continent transform plate boundary focuses rock uplift west of the Fairweather fault, southeast Alaska
Robert C. Witter, Harvey M. Kelsey, Richard O. Lease, Adrian Bender, Katherine M. Scharer, Peter J. Haeussler, Daniel S. Brothers
Natalia A. Ruppert, M. Jadamec, Jeffery T. Freymueller, editor(s)
2025, Book chapter, Tectonics and seismic structure of Alaska and northwestern Canada: EarthScope and beyond
Contraction along the Yakutat–North America plate boundary drives 4.6–9.0 mm/year Holocene rock uplift rates along Earth's fastest slipping (≥49 mm/year) ocean–continent transform fault, the Fairweather Fault. Between Icy Point and Lituya Bay, the near-vertical Fairweather fault focuses rock uplift and rapid right-lateral slip by accommodating both vertical and fault-parallel strain during oblique-slip...
