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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: 3110

Changes in rocky intertidal community structure during a marine heatwave in the northern Gulf of Alaska Changes in rocky intertidal community structure during a marine heatwave in the northern Gulf of Alaska

Marine heatwaves are global phenomena that can have major impacts on the structure and function of coastal ecosystems. By mid-2014, the Pacific Marine Heatwave (PMH) was evident in intertidal waters of the northern Gulf of Alaska and persisted for multiple years. While offshore marine ecosystems are known to respond to these warmer waters, the response of rocky intertidal ecosystems to...
Authors
Ben Weitzman, Brenda Konar, Katrin Iken, Heather Coletti, Daniel Monson, Robert M. Suryan, Thomas Dean, D. Hondolero, Mandy Lindeberg

Heatwave-induced synchrony within forage fish portfolio disrupts energy flow to top pelagic predators Heatwave-induced synchrony within forage fish portfolio disrupts energy flow to top pelagic predators

During the Pacific marine heatwave of 2014–2016, abundance and quality of several key forage fish species in the Gulf of Alaska were simultaneously reduced throughout the system. Capelin (Mallotus catervarius), sand lance (Ammodytes personatus), and herring (Clupea pallasii) populations were at historically low levels, and within this community abrupt declines in portfolio effects...
Authors
Mayumi L. Arimitsu, John F. Piatt, Scott Hatch, Robert M. Suryan, Sonia Batten, Mary Anne Bishop, Rob W. Campbell, Heather Coletti, Dan Cushing, Kristen Gorman, Russell R. Hopcroft, Kathy J. Kuletz, Caitlin Elizabeth Marsteller, Caitlin McKinstry, David McGowan, John Moran, W. Scott Pegau, Anne Schaefer, Sarah K. Schoen, Jan Straley, Vanessa R. von Biela

Airborne geophysical imaging of weak zones on Iliamna Volcano, Alaska: Implications for slope stability Airborne geophysical imaging of weak zones on Iliamna Volcano, Alaska: Implications for slope stability

Water‐saturated, hydrothermally altered rocks reduce the strength of volcanic edifices and increase the potential for sector collapses and far‐traveled mass flows of unconsolidated debris. Iliamna Volcano is an andesitic stratovolcano located on the western side of the Cook Inlet, ∼225 km southwest of Anchorage and is a source of repeated avalanches. The widespread snow and ice cover on...
Authors
Dana E. Peterson, Carol A. Finn, Paul A. Bedrosian

Timing and amount of southern Cascadia earthquake subsidence over the past 1700 years at northern Humboldt Bay, California, USA Timing and amount of southern Cascadia earthquake subsidence over the past 1700 years at northern Humboldt Bay, California, USA

Stratigraphic, lithologic, foraminiferal, and radiocarbon analyses indicate that at least four abrupt mud-over-peat contacts are recorded across three sites (Jacoby Creek, McDaniel Creek, and Mad River Slough) in northern Humboldt Bay, California, USA (∼44.8°N, −124.2°W). The stratigraphy records subsidence during past megathrust earthquakes at the southern Cascadia subduction zone ∼40...
Authors
Jason S. Padgett, Simon E. Engelhart, Harvey M. Kelsey, Robert C. Witter, Niamh Cahill, Eileen Hemphill-Haley

Ground‐penetrating radar, electromagnetic induction, terrain, and vegetation observations coupled with machine learning to map permafrost distribution at Twelvemile Lake, Alaska Ground‐penetrating radar, electromagnetic induction, terrain, and vegetation observations coupled with machine learning to map permafrost distribution at Twelvemile Lake, Alaska

We collected ground‐penetrating radar (GPR) and frequency‐domain electromagnetic induction (FDEM) profiles in 2011 and 2012 to identify the extent of permafrost relative to surface biomass and solar insolation around Twelvemile Lake near Fort Yukon, Alaska. We compared a Landsat‐derived biomass estimate and modeled solar insolation from a digital elevation model to the geophysical...
Authors
S. Campbell, Martin A. Briggs, S.P. Roy, T. A. Douglas, S. Saari

Multi-region assessment of chemical mixture exposures and predicted cumulative effects in USA wadeable urban/agriculture-gradient streams Multi-region assessment of chemical mixture exposures and predicted cumulative effects in USA wadeable urban/agriculture-gradient streams

Chemical-contaminant mixtures are widely reported in large stream reaches in urban/agriculture-developed watersheds, but mixture compositions and aggregate biological effects are less well understood in corresponding smaller headwaters, which comprise most of stream length, riparian connectivity, and spatial biodiversity. During 2014–2017, the U.S. Geological Survey (USGS) measured 389...
Authors
Paul M. Bradley, Celeste A. Journey, Kristin M. Romanok, Sara E. Breitmeyer, Daniel T. Button, Daren M. Carlisle, Bradley Huffman, Barbara Mahler, Lisa H. Nowell, Sharon L. Qi, Kelly L. Smalling, Ian R. Waite, Peter C. Van Metre

Tectonic and magmatic controls on the metallogenesis of porphyry deposits in Alaska Tectonic and magmatic controls on the metallogenesis of porphyry deposits in Alaska

Porphyry Cu and Mo deposits and occurrences are found throughout Alaska; they formed episodically during repeated subduction and arc-continent collisions spanning the Silurian to Quaternary. Porphyry systems occur in continental-margin and island arcs, which are broadly grouped into pre-accretionary or post-accretionary arcs. Pre-Mesozoic occurrences formed in continental or island arcs...
Authors
Douglas C. Kreiner, James V. Jones, Karen D. Kelley, Garth E. Graham

Sr, Nd, Hf and Pb isotope geochemistry of Early Miocene shoshonitic lavas from the South Fiji Basin: Note Sr, Nd, Hf and Pb isotope geochemistry of Early Miocene shoshonitic lavas from the South Fiji Basin: Note

We present new Sr, Nd, Hf and Pb isotope data for Early Miocene shoshonitic and high-K lavas dredged from seamounts in the South Fiji Basin, southwest Pacific Ocean. Our analyses provide a useful reference dataset for this distinctive compositional suite. The shoshonitic lavas formed in an intra-oceanic back-arc basin setting and are broadly coeval with nearby arc and back-arc basin...
Authors
Nick Mortimer, Delphine Bosch, Christine Laporte-Magoni, Erin Todd, James B Gill

Forecasting community reassembly using climate-linked spatio-temporal ecosystem models Forecasting community reassembly using climate-linked spatio-temporal ecosystem models

Ecosystems are increasingly impacted by human activities, altering linkages among physical and biological components. Spatial community reassembly occurs when these human impacts modify the spatial overlap between system components, and there is need for practical tools to forecast spatial community reassembly at landscape scales using monitoring data. To illustrate a new approach, we...
Authors
James Thorson, Mayumi L. Arimitsu, Lewis Barnett, Wei Cheng, Lisa Eisner, Alan Haynie, Albert Hermann, Kirsten Holsman, David Kimmel, Michael Lomas, Jon Richar, Elizabeth Siddon

Variability of lipids and fatty acids in Pacific walrus blubber Variability of lipids and fatty acids in Pacific walrus blubber

The variability of lipid content and fatty acid (FA) composition across blubber depth and body sites are important considerations for condition and diet studies of marine mammals. We investigated lipid and FA variability among inner and outer blubber layers, three body sites, four study years, and lactation status of adult female Pacific walruses (Odobenus rosmarus divergens) using...
Authors
Chadwick V. Jay, Sara J. Iverson, Anthony S. Fischbach

Native American fire management at an ancient wildland–urban interface in the Southwest United States Native American fire management at an ancient wildland–urban interface in the Southwest United States

The intersection of expanding human development and wildland landscapes—the “wildland–urban interface” or WUI—is one of the most vexing contexts for fire management because it involves complex interacting systems of people and nature. Here, we document the dynamism and stability of an ancient WUI that was apparently sustainable for more than 500 y. We combine ethnography, archaeology...
Authors
Christopher Roos, Thomas W. Swetnam, T. J. Ferguson, Matthew J. Liebmann, Rachel A. Loehman, John Welch, Ellis Q. Margolis, Christopher H. Guiterman, William Hockaday, Michael Aiuvalasit, Jenna Battillo, Joshua Farella, Christopher Kiahtipes
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