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: 2891
A simple method for in situ monitoring of water temperature in substrates used by spawning salmonids
Interstitial water temperature within spawning habitats of salmonids may differ from surface-water temperature depending on intragravel flow paths, geomorphic setting, or presence of groundwater. Because survival and developmental timing of salmon are partly controlled by temperature, monitoring temperature within gravels used by spawning salmonids is required to adequately describe the environmen
Authors
Christian E. Zimmerman, James E. Finn
Molecular detection of hematozoa infections in tundra swans relative to migration patterns and ecological conditions at breeding grounds
Tundra swans (Cygnus columbianus) are broadly distributed in North America, use a wide variety of habitats, and exhibit diverse migration strategies. We investigated patterns of hematozoa infection in three populations of tundra swans that breed in Alaska using satellite tracking to infer host movement and molecular techniques to assess the prevalence and genetic diversity of parasites. We evaluat
Authors
Andrew M. Ramey, Craig R. Ely, Joel A. Schmutz, John M. Pearce, Darryl J. Heard
Structure of marine predator and prey communities along environmental gradients in a glaciated fjord
Spatial patterns of marine predator communities are influenced to varying degrees by prey distribution and environmental gradients. We examined physical and biological attributes of an estuarine fjord with strong glacier influence to determine the factors that most influence the structure of predator and prey communities. Our results suggest that some species, such as walleye pollock (Theragra cha
Authors
Martin Renner, Mayumi L. Arimitsu, John F. Piatt
Moderating Argos location errors in animal tracking data
1. The Argos System is used worldwide to satellite-track free-ranging animals, but location errors can range from tens of metres to hundreds of kilometres. Low-quality locations (Argos classes A, 0, B and Z) dominate animal tracking data. Standard-quality animal tracking locations (Argos classes 3, 2 and 1) have larger errors than those reported in Argos manuals.
2. The Douglas Argos-filter (DAF)
Authors
David C. Douglas, Rolf Weinziert, Sarah C. Davidson, Roland Kays, Martin Wikelski, Gil Bohrer
Using surface velocities to calculate ice thickness and bed topography: A case study at Columbia Glacier, Alaska, USA
Information about glacier volume and ice thickness distribution is essential for many glaciological applications, but direct measurements of ice thickness can be difficult and costly. We present a new method that calculates ice thickness via an estimate of ice flux. We solve the familiar continuity equation between adjacent flowlines, which decreases the computational time required compared to a s
Authors
R.W. McNabb, R. Hock, Shad O'Neel, Lowell A. Rasmussen, Y. Ahn, M. Braun, H. Conway, S. Herreid, I. Joughin, W.T. Pfeffer, B.E. Smith, M. Truffer
High shrew diversity on Alaska's Seward Peninsula: Community assembly and environmental change
In September 2010, 6 species of shrews (genus: Sorex) were collected at a single locality on the Seward Peninsula of Alaska. Such high sympatric diversity within a single mammalian genus is seldom realized. This phenomenon at high latitudes highlights complex Arctic community dynamics that reflect significant turnover through time as a consequence of environmental change. Each of these shrew speci
Authors
Andrew G. Hope
Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska
We present the results of a reconnaissance investigation of unusual debris mass-movement features on permafrost slopes that pose a potential infrastructure hazard in the south-central Brooks Range, Alaska. For the purpose of this paper, we describe these features as frozen debris-lobes. We focus on the characterisation of frozen debris-lobes as indicators of various movement processes using ground
Authors
R.P. Daanen, G. Grosse, M.M. Darrow, T. D. Hamilton, Benjamin M. Jones
Chronic hydrocarbon exposure of harlequin ducks in areas affected by the Selendang Ayu oil spill at Unalaska Island, Alaska
We evaluated chronic exposure of harlequin ducks (Histrionicus histrionicus) to hydrocarbons associated with the 2004 M/V Selendang Ayu oil spill at Unalaska Island, Alaska. We measured levels of hepatic 7-ethoxyresorufin-O-deethylase activity (EROD) in liver biopsy samples as an indicator of hydrocarbon exposure in three oiled bays and one reference bay in 2005, 2006, and 2008. Median EROD activi
Authors
Paul L. Flint, J.L. Schamber, K.A. Trust, A.K. Miles, J.D. Henderson, B.W. Wilson
Food availability and offspring sex in a monogamous seabird: insights from an experimental approach
Sex allocation theory predicts that parents should favor offspring of the sex that provides the greatest fitness return. Despite growing evidence suggesting that vertebrates are able to overcome the constraint of chromosomal sex determination, the general pattern remains equivocal, indicating a need for experimental investigations. We used an experimental feeding design to study sex allocation dur
Authors
Thomas Merkling, Sarah Leclaire, Etienne Danchin, Emeline Lhuillier, Richard H. Wagner, Joël White, Scott A. Hatch, Pierrick Blanchard
Vegetation shifts observed in arctic tundra 17 years after fire
With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope of Alaska. Fire-related shifts in vegetation composition were assessed from remote-sensin
Authors
Kirsten Barrett, Adrian V. Rocha, Martine Janet van de Weg, Gaius Shaver
Listening to Glaciers: Passive hydroacoustics near marine-terminating glaciers
The catastrophic breakup of the Larsen B Ice Shelf in the Weddell Sea in 2002 paints a vivid portrait of the effects of glacier-climate interactions. This event, along with other unexpected episodes of rapid mass loss from marine-terminating glaciers (i.e., tidewater glaciers, outlet glaciers, ice streams, ice shelves) sparked intensified study of the boundaries where marine-terminating glaciers i
Authors
E.C. Pettit, J.A. Nystuen, Shad O'Neel
Thermokarst lakes, drainage, and drained basins
Thermokarst lakes and drained lake basins are widespread in Arctic and sub-Arctic permafrost lowlands with ice-rich sediments. Thermokarst lake formation is a dominant mode of permafrost degradation and is linked to surface disturbance, subsequent melting of ground ice, surface subsidence, water impoundment, and positive feedbacks between lake growth and permafrost thaw, whereas lake drainage gene
Authors
Guido Grosse, Benjamin M. Jones, Christopher D. Arp