Hail formation triggers rapid ash aggregation in volcanic plumes
Alexa R. Van Eaton, Larry G. Mastin, M. Herzog, Hans F. Schwaiger, David J. Schneider, Kristi L. Wallace, Amanda B Clarke
2015, Nature Communications (6)
During explosive eruptions, airborne particles collide and stick together, accelerating the fallout of volcanic ash and climate-forcing aerosols. This aggregation process remains a major source of uncertainty both in ash dispersal forecasting and interpretation of eruptions from the geological record. Here we illuminate the mechanisms and timescales of particle aggregation...
Landscape and local effects on occupancy and densities of an endangered wood-warbler in an urbanizing landscape
Jennifer Reidy, Frank R. Thompson III, Courtney L. Amundson, Lisa O’Donnell
2015, Landscape Ecology (31) 365-382
Context Golden-cheeked warblers (Setophaga chrysoparia), an endangered wood-warbler, breed exclusively in woodlands co-dominated by Ashe juniper (Juniperus ashei) in central Texas. Their breeding range is becoming increasingly urbanized and habitat loss and fragmentation are a main threat to the species’ viability. Objectives We investigated the...
Limits to benthic feeding by eiders in a vital Arctic migration corridor due to localized prey and changing sea ice
James R. Lovvorn, Aariel R. Rocha, Stephen C. Jewett, Douglas Dasher, Steffen Oppel, Abby Powell
2015, Progress in Oceanography (136) 162-174
Four species of threatened or declining eider ducks that nest in the Arctic migrate through the northeast Chukchi Sea, where anticipated industrial development may require prioritizing areas for conservation. In this nearshore corridor (10–40 m depth), the eiders’ access to benthic prey during the spring is restricted to variable areas of...
Mapping surficial minerals at high latitudes: The USGS 2014 imaging spectrometer data collection in Alaska
Raymond F. Kokaly, Todd M. Hoefen, Garth Graham, Karen Kelly, Michaela Johnson, Bernard Hubbard, Richard Goldfarb
2015, Conference Paper
Passive optical remote sensing of high latitude regions faces many challenges including a short acquisition season and poor illumination due to low solar elevation. Additional complications are encountered in the identification of surface minerals for mineral resource characterization because minerals of interest commonly are exposed on steep terrain, further challenging...
Preliminary interpretation of industry two-dimensional seismic data from Susitna Basin, south-central Alaska
Kristen A. Lewis, Christopher J. Potter, Anjana K. Shah, Richard G. Stanley, Peter J. Haeussler, Richard W. Saltus
2015, Open-File Report 2015-1138
Located approximately 80 kilometers northwest of Anchorage, Alaska, the Susitna Basin is a complex sedimentary basin whose tectonic history has been poorly understood. Recent interpretation of two-dimensional seismic reflection data integrated with well, aeromagnetic, and gravity data provides new insights into the structural and stratigraphic nature of the basin. This report...
Potential for real‐time understanding of coupled hydrologic and biogeochemical processes in stream ecosystems: Future integration of telemetered data with process models for glacial meltwater streams
Diane M. McKnight, Karen D. Cozzetto, James D. S. Cullis, Michael N. Gooseff, Christopher Jaros, Joshua C. Koch, W. Berry Lyons, Roseanna M. Neupauer, Adam N. Wlostowski
2015, Water Resources Research (51) 6725-6738
While continuous monitoring of streamflow and temperature has been common for some time, there is great potential to expand continuous monitoring to include water quality parameters such as nutrients, turbidity, oxygen, and dissolved organic material. In many systems, distinguishing between watershed and stream ecosystem controls can be challenging. The usefulness...
Geologic Map of Baranof Island, southeastern Alaska
Susan M. Karl, Peter J. Haeussler, Glen R. Himmelberg, Cathy L. Zumsteg, Paul W. Layer, Richard M. Friedman, Sarah M. Roeske, Lawrence W. Snee
2015, Scientific Investigations Map 3335
This map updates the geology of Baranof Island based on fieldwork, petrographic analyses, paleontologic ages, and isotopic ages. These new data provide constraints on depositional and metamorphic ages of lithostratigraphic rock units and the timing of structures that separate them. Kinematic analyses and thermobarometric calculations provide insights on the regional...
Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane
Frederic H. Wilson, Robert L. Detterman, Gregory D. DuBois
2015, Bulletin 1969-B
The Alaska Peninsula is composed of the late Paleozoic to Quaternary sedimentary, igneous, and minor metamorphic rocks that record the history of a number of magmatic arcs. These magmatic arcs include an unnamed Late Triassic(?) and Early Jurassic island arc, the early Cenozoic Meshik arc, and the late Cenozoic Aleutian...
Surface melt dominates Alaska glacier mass balance
Larsen Chris F, E Burgess, A.A. Arendt, Shad O’Neel, A. J. Johnson, C. Kienholz
2015, Geophysical Research Letters (42) 5902-5908
Mountain glaciers comprise a small and widely distributed fraction of the world's terrestrial ice, yet their rapid losses presently drive a large percentage of the cryosphere's contribution to sea level rise. Regional mass balance assessments are challenging over large glacier populations due to remote and rugged geography, variable response of...
USGS Arctic Science Strategy
Mark Shasby, Durelle Smith
2015, Fact Sheet 2015-3049
The United States is one of eight Arctic nations responsible for the stewardship of a polar region undergoing dramatic environmental, social, and economic changes. Although warming and cooling cycles have occurred over millennia in the Arctic region, the current warming trend is unlike anything recorded previously and is affecting the...
Geospatial compilation of results from field sample collection in support of mineral resource investigations, Western Alaska Range, Alaska, July 2013
Michaela R. Johnson, Garth E. Graham, Bernard E. Hubbard, William Benzel
2015, Data Series 943
This Data Series summarizes results from July 2013 sampling in the western Alaska Range near Mount Estelle, Alaska. The fieldwork combined in situ and camp-based spectral measurements of talus/soil and rock samples. Five rock and 48 soil samples were submitted for quantitative geochemical analysis (for 55 major and trace elements),...
User’s guide to the North Pacific Pelagic Seabird Database 2.0
Gary S. Drew, John F. Piatt, Martin Renner
2015, Open-File Report 2015-1123
The North Pacific Pelagic Seabird Database (NPPSD) was created in 2005 to consolidate data on the oceanic distribution of marine bird species in the North Pacific. Most of these data were collected on surveys by counting species within defined areas and at known locations (that is, on strip transects). The...
Estimating the abundance of the Southern Hudson Bay polar bear subpopulation with aerial surveys
Martyn E. Obbard, Seth P. Stapleton, Kevin R. Middel, Isabelle Thibault, Vincent Brodeur, Charles Jutras
2015, Polar Biology (38) 1713-1725
The Southern Hudson Bay (SH) polar bear subpopulation occurs at the southern extent of the species’ range. Although capture–recapture studies indicate abundance was likely unchanged between 1986 and 2005, declines in body condition and survival occurred during the period, possibly foreshadowing a future decrease in abundance. To obtain a current...
Monitoring population status of sea otters (Enhydra lutris) in Glacier Bay National Park and Preserve, Alaska: options and considerations
George G. Esslinger, Daniel Esler, S. Howlin, L.A. Starcevich
2015, Open-File Report 2015-1119
After many decades of absence from southeast Alaska, sea otters (Enhydra lutris) are recolonizing parts of their former range, including Glacier Bay, Alaska. Sea otters are well known for structuring nearshore ecosystems and causing community-level changes such as increases in kelp abundance and changes in the size and number of...
Age-specific vibrissae growth rates: a tool for determining the timing of ecologically important events in Steller sea lions
L.D. Rea, A.M. Christ, A.B. Hayden, V.K. Stegall, S.D. Farley, Craig A. Stricker, J.E. Mellish, John M. Maniscalco, J.N. Waite, V.N. Burkanov, K.W. Pitcher
2015, Marine Mammal Science (31) 1213-1233
Steller sea lions (SSL; Eumetopias jubatus) grow their vibrissae continually, providing a multiyear record suitable for ecological and physiological studies based on stable isotopes. An accurate age-specific vibrissae growth rate is essential for registering a chronology along the length of the record, and for interpreting the timing of ecologically important events....
Summer declines in activity and body temperature offer polar bears limited energy savings
J.P. Whiteman, H.J. Harlow, George M. Durner, R. Anderson-Sprecher, Shannon E. Albeke, Eric V. Regehr, Steven C. Amstrup, M. Ben-David
2015, Science (349) 295-298
Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of...
National assessment of shoreline change: historical change along the north coast of Alaska, U.S.-Canadian border to Icy Cape
Ann E. Gibbs, Bruce M. Richmond
2015, Open-File Report 2015-1048
Beach erosion is a persistent problem along most open-ocean shores of the United States. Along the Arctic coast of Alaska, coastal erosion is widespread, may be accelerating, and is threatening defense and energy-related infrastructure, coastal habitats, and Native communities. As coastal populations continue to expand and infrastructure and habitat are...
National assessment of shoreline change: a GIS compilation of vector shorelines and associated shoreline change data for the north coast of Alaska, U.S.-Canadian border to Icy Cape
Ann E. Gibbs, Karen A. Ohman, Bruce M. Richmond
2015, Open-File Report 2015-1030
The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native communities, and encompasses unique habitats of global significance. Coastal erosion along the Arctic coast is chronic, widespread, and may be accelerating, which threatens defense- and energy-related infrastructure,...
Tsunami recurrence in the eastern Alaska-Aleutian arc: A Holocene stratigraphic record from Chirikof Island, Alaska
Alan R. Nelson, Richard W. Briggs, Tina Dura, Simon E. Engelhart, Guy Gelfenbaum, Lee-Ann Bradley, S.L. Forman, Christopher H. Vane, K.A. Kelley
2015, Geosphere (11) 1203
Despite the role of the Alaska-Aleutian megathrust as the source of some of the largest earthquakes and tsunamis, the history of its pre–twentieth century tsunamis is largely unknown west of the rupture zone of the great (magnitude, M 9.2) 1964 earthquake. Stratigraphy in core transects at two boggy lowland sites...
Tectonic and sedimentary linkages between the Belt-Purcell basin and southwestern Laurentia during the Mesoproterozoic ca. 1.60-1.40 Ga
James V. Jones III, Christohper G Dainel, Michael F Doe
2015, Lithosphere (7) 465-472
Mesoproterozoic sedimentary basins in western North America provide key constraints on pre-Rodinia craton positions and interactions along the western rifted margin of Laurentia. One such basin, the Belt-Purcell basin, extends from southern Idaho into southern British Columbia and contains a >18-km-thick succession of siliciclastic sediment deposited ca. 1.47–1.40 Ga. The...
Soil surface organic layers in Arctic Alaska: spatial distribution, rates of formation, and microclimatic effects
Carson Baughman, Daniel H. Mann, David L. Verbyla, Michael L. Kunz
2015, Journal of Geophysical Research: Biogeosciences (120) 1150-1164
Organic layers of living and dead vegetation cover the ground surface in many permafrost landscapes and play important roles in ecosystem processes. These soil surface organic layers (SSOLs) store large amounts of carbon and buffer the underlying permafrost and its contained carbon from changes in aboveground climate. Understanding the dynamics of SSOLs...
Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska
Melanie B. Werdon, Matthew Granitto, Jaime S. Azain
2015, Report
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and...
Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Kougarok area, Bendeleben and Teller quadrangles, Seward Peninsula, Alaska
Melanie B. Werdon, Matthew Granitto, Jaime S. Azain
2015, Report, Alaska Division of Geological & Geophysical Surveys
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and...
Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Haines area, Juneau and Skagway quadrangles, southeast Alaska
Melanie B. Werdon, Matthew Granitto, Jaime S. Azain
2015, Report
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and...
Hydrogeochemical exploration: a reconnaissance study on northeastern Seward Peninsula, Alaska
Garth E. Graham, Ryan D. Taylor, Steve Buckley
Julie A. Dumoulin, editor(s)
2015, Professional Paper 1814-A
A reconnaissance hydrogeochemical study employing high-resolution/high-sensitivity inductively coupled plasma mass spectrometry analysis of stream and seep water samples (n= 171) was conducted in an area of limited bedrock exposure on the northeastern Seward Peninsula, Alaska. Sampling was focused in drainages around four main areas—at the Anugi Pb-Zn-Ag occurrence and in...
