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: 3091
Basalt geochemistry and mantle flow during early backarc basin evolution: Havre Trough and Kermadec Arc, southwest Pacific Basalt geochemistry and mantle flow during early backarc basin evolution: Havre Trough and Kermadec Arc, southwest Pacific
The Havre Trough (HT) backarc basin in the southwest Pacific is in the rifting stage of development. We distinguish five types of basalt there based on their amount and kind of slab component: backarc basalts (BAB) with little or no slab component, modified BAB with slight amounts, reararc (RA) with more, remnants of the preexisting arc (Colville Ridge horsts), and arc front volcanoes...
Authors
James B Gill, Kaj Hoernle, Erin Todd, Folkmar Hauff, Reinhard Werner, Christian Timm, Dieter Garbe-Schönberg, Marcus Gutjahr
Record fledging count from a seven-egg clutch in the Cooper’s Hawk (Accipiter cooperii) Record fledging count from a seven-egg clutch in the Cooper’s Hawk (Accipiter cooperii)
Cooper's Hawks (Accipiter cooperii) typically lay 3–5 eggs per clutch, rarely 6 eggs, and there are 2 accounts of 7-egg clutches and 1 record of a maximum 8-egg clutch for the species. Brood sizes of 3–5 young are common and the previous maximum brood count is 6 young. However, in 2019, we found an urban nest in Stevens Point, Wisconsin, with 7 eggs that resulted in a record high of 7...
Authors
Robert N. Rosenfield, Sarah A. Sonsthagen, Ann Elizabeth Riddle-Berntsen, Evan Kuhel
Polar Bear (Ursus maritimus) Polar Bear (Ursus maritimus)
This chapter comprises the following sections: names, taxonomy, subspecies and distribution, descriptive notes, habitat, movements and home range, activity patterns, feeding ecology, reproduction and growth, behavior, parasites and diseases, status in the wild, and status in captivity.
Authors
Karyn D. Rode, Martyn E. Obbard, Stanislav Belikov, Andrew E. Derocher, George M. Durner, Gregory Thiemann, Morten Tryland, Robert J. Letcher, Randi Meyersen, Christian Sonne, Bjorn Jenssen, Rune Dietz, Dag Vongraven
How Is climate change affecting polar bears and giant pandas? How Is climate change affecting polar bears and giant pandas?
Anthropogenic greenhouse gas emissions are the primary cause of climate change and an estimated increase of 3.7 to 4.8 °C is predicted by the year 2100 if emissions continue at current levels. Polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca) provide an interesting comparison study of the impact of climate change on bear species. While polar bears and giant pandas...
Authors
Melissa Songer, Todd C. Atwood, David C. Douglas, Qiongyu Huang, Renqiang Li, Nicholas Pilfold, Ming Xu, George M. Durner
Generation of calc-alkaline magmas during crystallization at high oxygen fugacity: An experimental and petrologic study of tephras from Buldir Volcano, western Aleutian Arc, Alaska, USA Generation of calc-alkaline magmas during crystallization at high oxygen fugacity: An experimental and petrologic study of tephras from Buldir Volcano, western Aleutian Arc, Alaska, USA
Despite agreement that calc-alkaline volcanism occurs at subduction zones and is responsible for the genesis of continental landmasses, there is no consensus on the source of the Fe-depleted signature hallmark to calc-alkaline volcanism. In this study, we utilize mafic tephras collected from Buldir Volcano to address the genesis of strongly calc-alkaline volcanic rocks (those with a low...
Authors
Laura Waters, Elizabeth Cottrell, Michelle L. Coombs, Katherine A. Kelley
Seabird synthesis Seabird synthesis
Overall, the status of seabirds was fair to good in the WGOA in 2020, with limited data available from Middleton Island, Cook Inlet, and the Kodiak Archipelago (Figure 63). Colony attendance remains low in some populations compared to historic levels, and some colonies were newly abandoned. However, when birds did arrive to breed, reproductive success generally appeared fair to good for...
Authors
Mayumi L. Arimitsu, Hillary K. Burgess, Robin Corcoran, Scott Hatch, Tim Jones, Jackie Lindsey, Caitlin Elizabeth Marsteller, John F. Piatt, Sarah K. Schoen
Exploring overlap of feather molting and migration in Tundra Swans using δ2H analysis Exploring overlap of feather molting and migration in Tundra Swans using δ2H analysis
Determining the processes that shape the relative timing of energetically-costly events in the annual cycle of migrating birds is important to our understanding of avian phenology and ecology. We paired satellite tracking and hydrogen stable isotope analysis (δ2H) to examine the relative timing of two such events – migration and feather molting – in tundra swans from four breeding areas...
Authors
Nathan Wolf, T. Scott Smeltz, Jeffrey Welker, Matthew Rogers, Craig R. Ely
Shorebird reproductive response to exceptionally early and late springs varies across sites in Arctic Alaska Shorebird reproductive response to exceptionally early and late springs varies across sites in Arctic Alaska
While increases in overall temperatures are widely reported in the Arctic, large inter-annual variation in spring weather, with extreme early and late conditions, is also occurring. Using data collected from three sites in Arctic Alaska, we explored how shorebird breeding density, nest initiation, nest synchrony, nest survival, and phenological mismatch varied between two exceptionally...
Authors
Rebecca L McGuire, Richard B. Lanctot, Sarah T. Saalfeld, Daniel R. Ruthrauff, Joe Liebezeit
Shorebird research at the U.S. Geological Survey Alaska Science Center Shorebird research at the U.S. Geological Survey Alaska Science Center
Shorebirds—which include sandpipers, plovers, and oystercatchers—are perhaps best known by their presence on sandy beaches, running along the water’s edge while they probe for food. But they are probably less recognized for their impressive long-distance migrations. Millions of individuals travel from across the globe to breed throughout Alaska each spring, making these birds a familiar...
Authors
Dan Ruthrauff, T. Lee Tibbitts, John Pearce
Migration routes and population status of the Brent Goose Branta bernicla nigricans wintering in East Asia Migration routes and population status of the Brent Goose Branta bernicla nigricans wintering in East Asia
Of the world’s Brent Goose Branta bernicla populations, the migration routes and winter distribution of the East Asian population of Brent Geese B. b. nigricans are the least well known. We therefore marked Brent Geese at their primary pre-migratory staging area in Notsuke Bay, Hokkaido, Japan to describe their migration between breeding and wintering areas in East Asia. Additionally...
Authors
Yusuke Sawa, Chieko Tamura, Toshio Ikeuchi, Kaoru Fujii, Aisa Ishioroshi, T. Shimada, Shiro Tatsuzawa, Xueqin Deng, Lei Cao, Hwajung Kim, David H. Ward
Using hair cortisol to assess physiological stress in Alaska polar bears Using hair cortisol to assess physiological stress in Alaska polar bears
The concentration of cortisol in hair (HCC) of polar bears (Ursus maritimus) may provide a retrospective view of physiological stress they experience and a link to their response to environmental change. To understand this relationship, we assayed HCC from polar bears captured in the Alaska Beaufort, Bering and Chukchi seas during 1983–1989 and 2004–2016. Cortisol accumulated in hair...
Authors
George M. Durner
Detection and assessment of a large and potentially tsunamigenic periglacial landslide in Barry Arm, Alaska Detection and assessment of a large and potentially tsunamigenic periglacial landslide in Barry Arm, Alaska
The retreat of glaciers in response to global warming has the potential to trigger landslides in glaciated regions around the globe. Landslides that enter fjords or lakes can cause tsunamis, which endanger people and infrastructure far from the landslide itself. Here we document the ongoing movement of an unstable slope (total volume of 455 million m3) in Barry Arm, a fjord in Prince...
Authors
Chunli Dai, Bretwood Higman, Patrick J. Lynett, Mylene Jacquemart, Ian Howat, Anna K. Liljedahl, Anja Dufresne, Jeffery T. Freymueller, Marten Geertsema, Melissa Ward Jones, Peter J. Haeussler