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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

Predicting effects of environmental change on a migratory herbivore

Changes in climate, food abundance and disturbance from humans threaten the ability of species to successfully use stopover sites and migrate between non‐breeding and breeding areas. To devise successful conservation strategies for migratory species we need to be able to predict how such changes will affect both individuals and populations. Such predictions should ideally be process‐based, focusin
Authors
R. A. Stillman, K. A. Wood, Whelan Gilkerson, E. Elkinton, J. M. Black, David H. Ward, M. Petrie

Monitoring digestibility of forages for herbivores: a new application for an old approach

Ruminant populations are often limited by how well individuals are able to acquire nutrients for growth, maintenance, and reproduction. Nutrient supply to the animal is dictated by the concentration of nutrients in feeds and the efficiency of digesting those nutrients (i.e., digestibility). Many different methods have been used to measure digestibility of forages for wild herbivores, all of which
Authors
Lindsey L. Vansomeren, Perry S. Barboza, Daniel P. Thompson, David D. Gustine

Arctic biodiversity: Increasing richness accompanies shrinking refugia for a cold-associated tundra fauna

As ancestral biodiversity responded dynamically to late-Quaternary climate changes, so are extant organisms responding to the warming trajectory of the Anthropocene. Ecological predictive modeling, statistical hypothesis tests, and genetic signatures of demographic change can provide a powerful integrated toolset for investigating these biodiversity responses to climate change, and relative resili
Authors
Andrew G. Hope, Eric Waltari, Jason L. Malaney, David C. Payer, J.A. Cook, Sandra L. Talbot

GIS-Based Identification of Areas with Mineral Resource Potential for Six Selected Deposit Groups, Bureau of Land Management Central Yukon Planning Area, Alaska

This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and paleoplacer
Authors
James V. Jones, Susan M. Karl, Keith A. Labay, Nora B. Shew, Matthew Granitto, Timothy S. Hayes, Jeffrey L. Mauk, Jeanine M. Schmidt, Erin Todd, Bronwen Wang, Melanie B. Werdon, Douglas B. Yager

Effects of simple acid leaching of crushed and powdered geological materials on high-precision Pb isotope analyses

We present new results of simple acid leaching experiments on the Pb isotope composition of USGS standard reference material powders and on ocean island basalt whole rock splits and powders. Rock samples were leached with cold 6 N HCl in an ultrasonic bath, then on a hot plate, and washed with ultrapure H2O before sample digestion in HF‐HNO3 and chromatographic purification of Pb. Lead isotope ana
Authors
Erin Todd, Andreas Stracke, Erik Scherer

Introduction to the special issue on the 2012 Haida Gwaii and 2013 Craig earthquakes at the Pacific–North America plate boundary (British Columbia and Alaska)

The 27 October 2012 Mw 7.8 Haida Gwaii thrust earthquake and the 5 January 2013 Mw 7.5 Craig strike‐slip earthquake are the focus of this special issue. They occurred along the transform boundary between the Pacific and North American plates (Fig. 1). The most identifiable feature of the plate boundary, the strike‐slip Queen Charlotte fault, might be viewed as typical of continent–ocean transform
Authors
Thomas S. James, John F. Cassidy, Garry C. Rogers, Peter J. Haeussler

Stratigraphic and microfossil evidence for a 4500-year history of Cascadia subduction zone earthquakes and tsunamis at Yaquina River estuary, Oregon, USA

The Sallys Bend swamp and marsh area on the central Oregon coast onshore of the Cascadia subduction zone contains a sequence of buried coastal wetland soils that extends back ∼4500 yr B.P. The upper 10 of the 12 soils are represented in multiple cores. Each soil is abruptly overlain by a sandy deposit and then, in most cases, by greater than 10 cm of mud. For eight of the 10 buried soils, times of
Authors
Nicholas A Graehl, Harvey M. Kelsey, Robert C. Witter, Eileen Hemphill-Haley, Simon E. Engelhart

Ways to be different: Foraging adaptations that facilitate higher intake rates in a northerly wintering shorebird compared with a low-latitude conspecific

At what phenotypic level do closely related subspecies that live in different environments differ with respect to food detection, ingestion and processing? This question motivated an experimental study on rock sandpipers (Calidris ptilocnemis). The species' nonbreeding range spans 20 deg of latitude, the extremes of which are inhabited by two subspecies: C. p. ptilocnemis that winters primarily in
Authors
Daniel R. Ruthrauff, Anne Dekinga, Robert E. Gill, Jan A. van Gils, Theunis Piersma

Oceanic and atmospheric forcing of Larsen C Ice-Shelf thinning

The catastrophic collapses of Larsen A and B ice shelves on the eastern Antarctic Peninsula have caused their tributary glaciers to accelerate, contributing to sea-level rise and freshening the Antarctic Bottom Water formed nearby. The surface of Larsen C Ice Shelf (LCIS), the largest ice shelf on the peninsula, is lowering. This could be caused by unbalanced ocean melting (ice loss) or enhanced f
Authors
P. R. Holland, A. Brisbourne, H. F. J. Corr, Daniel Mcgrath, K. Purdon, J. Paden, H. A. Fricker, F. S. Paolo, A.H. Fleming

Evidence for intercontinental parasite exchange through molecular detection and characterization of haematozoa in northern pintails (Anas acuta) sampled throughout the North Pacific Basin

Empirical evidence supports wild birds as playing a role in the interhemispheric exchange of bacteria and viruses; however, data supporting the redistribution of parasites among continents are limited. In this study, the hypothesis that migratory birds contribute to the redistribution of parasites between continents was tested by sampling northern pintails (Anas acuta) at locations throughout the
Authors
Andrew M. Ramey, Joel A. Schmutz, John A. Reed, Go Fujita, Bradley D. Scotton, Bruce Casler, Joseph P. Fleskes, Kan Konishi, Kiyoshi Uchida, Michael J. Yabsley

Historic and Contemporary Status of Sea Otters in the North Pacific

Similar to other species that in recent centuries experienced unregulated human exploitation, sea otters were extirpated throughout large portions of their historic range in the North Pacific. For most of the twentieth century, with cessation of the fur trade and because of concerted efforts at conservation, sea otters recovered much of their historic range and abundance. Late in the twentieth cen
Authors
James L. Bodkin

Challenges to sea otter recovery and conservation

Similar to other species that in recent centuries experienced unregulated human exploitation, sea otters were extirpated throughout large portions of their historic range in the North Pacific. For most of the twentieth century, with cessation of the fur trade and because of concerted efforts at conservation, sea otters recovered much of their historic range and abundance. Late in the twentieth cen
Authors
Brenda E. Ballachey, James L. Bodkin