Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

11286 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 62, results 1526 - 1550

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites
George R. Priest, Robert C. Witter, Yinglong J. Zhang, Chris Goldfinger, Kelin Wang, Jonathan C. Allan
2017, Natural Hazards (88) 285-313
Forecasting earthquake and tsunami hazards along the southern Cascadia subduction zone is complicated by uncertainties in the amount of megathrust fault slip during past ruptures. Here, we estimate slip on hypothetical ruptures of the southern part of the megathrust through comparisons of late Holocene Cascadia earthquake histories derived from tsunami...
Climate-induced trends in predator–prey synchrony differ across life-history stages of an anadromous salmonid
Donovan A. Bell, Ryan Kovach, Scott C. Vulstek, John E. Joyce, David A. Tallmon
2017, Canadian Journal of Fisheries and Aquatic Sciences (74) 1431-1438
Differential climate-induced shifts in phenology can create mismatches between predators and prey, but few studies have examined predator–prey mismatch across multiple life-history stages. We used long-term data from a warming stream with shifting salmonid migration timings to quantify intra-annual migration synchrony between predatory Dolly Varden (Salvelinus malma) and Pacific salmon...
Rapid response for invasive waterweeds at the arctic invasion front: Assessment of collateral impacts from herbicide treatments
Suresh Sethi, Michael P. Carey, John M. Morton, Edgar Guerron-Orejuela, Robert Decino, Mark Willette, James Boersma, Jillian Jablonski, Cheryl Anderson
2017, Biological Conservation (212) 300-309
The remoteness of subarctic and arctic ecosystems no longer protects against invasive species introductions. Rather, the mix of urban hubs surrounded by undeveloped expanses creates a ratchet process whereby anthropogenic activity is sufficient to introduce and spread invaders, but for which the costs of monitoring and managing remote ecosystems is...
CO2 time series patterns in contrasting headwater streams of North America
John T. Crawford, Emily H. Stanley, Mark M. Dornblaser, Robert G. Striegl
2017, Aquatic Sciences (79) 473-486
We explored the underlying patterns of temporal stream CO2 partial pressure (pCO2) variability using highfrequency sensors in seven disparate headwater streams distributed across the northern hemisphere. We also compared this dataset of [40,000 pCO2 records with other published records from lotic systems. Individual stream sites exhibited relatively distinct pCO2 patterns...
Historical and projected trends in landscape drivers affecting carbon dynamics in Alaska
Neal J. Pastick, Paul A. Duffy, Hélène Genet, T. Scott Rupp, Bruce K. Wylie, Kristofer Johnson, M. Torre Jorgenson, Norman B. Bliss, Anthony D. McGuire, Elchin Jafarov, Joseph F. Knight
2017, Ecological Applications (27) 1383-1402
Modern climate change in Alaska has resulted in widespread thawing of permafrost, increased fire activity, and extensive changes in vegetation characteristics that have significant consequences for socioecological systems. Despite observations of the heightened sensitivity of these systems to change, there has not been a comprehensive assessment of factors that drive...
Detect and exploit hidden structure in fatty acid signature data
Jeffrey F. Bromaghin, Suzanne M. Budge, Gregory W. Thiemann
2017, Ecosphere (8)
Estimates of predator diet composition are essential to our understanding of their ecology. Although several methods of estimating diet are practiced, methods based on biomarkers have become increasingly common. Quantitative fatty acid signature analysis (QFASA) is a popular method that continues to be refined and extended. Quantitative fatty acid signature...
Hydrologic impacts of changes in climate and glacier extent in the Gulf of Alaska watershed
Jordan Beamer, Dave Hill, Daniel Mcgrath, Anthony A. Arendt, Christian Kienholz
2017, Water Resources Research (53) 7502-7520
High‐resolution regional‐scale hydrologic models were used to quantify the response of late 21st century runoff from the Gulf of Alaska (GOA) watershed to changes in regional climate and glacier extent. NCEP Climate Forecast System Reanalysis data were combined with five Coupled Model Intercomparison Project Phase 5 general circulation models (GCMs)...
Tracer-based evidence of heterogeneity in subsurface flow and storage within a boreal hillslope
Joshua C. Koch, Ryan C. Toohey, D.M. Reeves
2017, Hydrological Processes (31) 2453-2463
Runoff from boreal hillslopes is often affected by distinct soil boundaries, including the frozen boundary and the organic – mineral boundary (OMB), where highly porous and hydraulically-conductive organic material overlies fine-grained mineral soils. Viewed from the surface, ground cover appears as a patchwork on sub-meter scales, with thick, moss mats...
Inland waters and their role in the carbon cycle of Alaska
Sarah M. Stackpoole, David E. Butman, David W. Clow, Kristine L. Verdin, Benjamin V. Gaglioti, Hélène Genet, Robert G. Striegl
2017, Ecological Applications (27) 1403-1420
The magnitude of Alaska (AK) inland waters carbon (C) fluxes is likely to change in the future due to amplified climate warming impacts on the hydrology and biogeochemical processes in high latitude regions. Although current estimates of major aquatic C fluxes represent an essential baseline against which future change can be...
Increased Arctic sea ice drift alters adult female polar bear movements and energetics
George M. Durner, David C. Douglas, Shannon Albeke, John P. Whiteman, Steven C. Amstrup, Evan Richardson, Ryan H. Wilson, Merav Ben-David
2017, Global Change Biology (23) 3460-3473
Recent reductions in thickness and extent have increased drift rates of Arctic sea ice. Increased ice drift could significantly affect the movements and the energy balance of polar bears (Ursus maritimus) which forage, nearly exclusively, on this substrate. We used radio-tracking and ice drift data to quantify the influence of...
PeRL: A circum-Arctic Permafrost Region Pond and Lake database
Sina Muster, Kurt Roth, Moritz Langer, Stephan Lange, Fabio Cresto Aleina, Annett Bartsch, Anne Morgenstern, Guido Grosse, Benjamin M. Jones, A. B. K. Sannel, Ylva Sjoberg, Frank Gunther, Christian Andresen, Alexandra Veremeeva, Prajna R. Lindgren, Frederic Bouchard, Mark J. Lara, Daniel Fortier, Simon Charbonneau, Tarmo A. Virtanen, Gustaf Hugelius, J. Palmtag, Matthias B. Siewert, William J. Riley, Charles Koven, Julia Boike
2017, Earth System Science Data (9) 317-348
Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost...
Puffins reveal contrasting relationships between forage fish and ocean climate in the North Pacific
William J. Sydeman, John F. Piatt, Sarah Ann Thompson, Marisol Garcia-Reyes, Scott A. Hatch, Mayumi L. Arimitsu, Leslie Slater, Jeffrey C. Williams, Nora A. Rojek, Stephani G. Zador, Heather M. Renner
2017, Fisheries Oceanography (26) 379-395
Long-term studies of predator food habits (i.e., ‘predator-based sampling’) are useful for identifying patterns of spatial and temporal variability of forage nekton in marine ecosystems. We investigated temporal changes in forage fish availability and relationships to ocean climate by analyzing diet composition of three puffin species (horned puffin Fratercula corniculata, tufted...
Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska
Anna K. Lilledahl, Anne Gadeke, Shad O’Neel, T. A. Gatesman, T. A. Douglas
2017, Geophysical Research Letters (44) 6876-6885
Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2),...
Morphological and molecular characterization of Sarcocystis arctica-like sarcocysts from the Arctic fox (Vulpes lagopus) from Alaska, USA
Camila K. Cerqueira-Cezar, Peter C. Thompson, Shiv K. Verma, Joseph Mowery, Rafael Calero-Bernal, Fernando H. Antunes Murata, David R. Sinnett, Caroline R. Van Hemert, Benjamin M. Rosenthal, Jitender P. Dubey
2017, Parasitology Research (116) 1871-1878
The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of...
Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic
Megan V. Ross, Ray T. Alisaukas, David C. Douglas, Dana K. Kellett
2017, Ecology (98) 1869-1883
A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological...
Genetic assessment of the effects of streamscape succession on coho salmon Oncorhynchus kisutch colonization in recently deglaciated streams
Kim T. Scribner, Chad Soiseth, Jeffrey J. McGuire, G. Kevin Sage, Lyman K. Thorsteinson, J. L. Nielsen, E. Knudsen
2017, Journal of Fish Biology (91) 195-218
Measures of genetic diversity within and among populations and historical geomorphological data on stream landscapes were used in model simulations based on approximate Bayesian computation (ABC) to examine hypotheses of the relative importance of stream features (geomorphology and age) associated with colonization events and gene flow for coho salmon Oncorhynchus kisutch breeding...
Autonomous acoustic recorders reveal complex patterns in avian detection probability
Sarah J. Thompson, Colleen M. Handel, Lance B. McNew
2017, Journal of Wildlife Management (81) 1228-1241
Avian point‐count surveys are typically designed to occur during periods when birds are consistently active and singing, but seasonal and diurnal patterns of detection probability are often not well understood and may vary regionally or between years. We deployed autonomous acoustic recorders to assess how avian availability for detection (i.e.,...
Landsat-based trend analysis of lake dynamics across northern permafrost regions
Ingmar Nitze, Guido Grosse, Benjamin M. Jones, Christopher D. Arp, Mathias Ulrich, Alexander Federov, Alexandra Veremeeva
2017, Remote Sensing (9)
Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding...
New methodology for computing tsunami generation by subaerial landslides: Application to the 2015 Tyndall Glacier landslide, Alaska
David L. George, Richard M. Iverson, Charles M. Cannon
2017, Geophysical Research Letters (44) 7276-7284
Landslide-generated tsunamis pose significant hazards and involve complex, multiphase physics that are challenging to model. We present a new methodology in which our depth-averaged two-phase model D-Claw is used to seamlessly simulate all stages of landslide dynamics as well as tsunami generation, propagation, and inundation. Because the model describes the...
Younger-Dryas cooling and sea-ice feedbacks were prominent features of the Pleistocene-Holocene transition in Arctic Alaska
Benjamin V. Gaglioti, Daniel H. Mann, Matthew J. Wooller, Benjamin M. Jones, Gregory C. Wiles, Pamela Groves, Michael L. Kunz, Carson Baughman, Richard E. Reanier
2017, Quaternary Science Reviews (169) 330-343
Declining sea-ice extent is currently amplifying climate warming in the Arctic. Instrumental records at high latitudes are too short-term to provide sufficient historical context for these trends, so paleoclimate archives are needed to better understand the functioning of the sea ice-albedo feedback. Here we use the oxygen isotope values of...
A genetic signature of the evolution of loss of flight in the Galapagos cormorant
Alejandro Burga, Weiguang Wang, Eyal Ben-David, Paul C. Wolf, Andrew M. Ramey, Claudio Verdugo, Karen Lyons, Patricia G. Parker, Leonid Kruglyak
2017, Science (356)
INTRODUCTIONChanges in the size and proportion of limbs and other structures have played a key role in the evolution of species. One common class of limb modification is recurrent wing reduction and loss of flight in birds. Indeed, Darwin used the occurrence of flightless birds as an...
Expanding the North American Breeding Bird Survey analysis to include additional species and regions
John R. Sauer, Daniel Niven, Keith L. Pardieck, David Ziolkowski Jr., William A. Link
2017, Journal of Fish and Wildlife Management (8) 154-172
The North American Breeding Bird Survey (BBS) contains data for >700 bird species, but analyses often focus on a core group of ∼420 species. We analyzed data for 122 species of North American birds for which data exist in the North American Breeding Bird Survey (BBS) database but are not...
Migration trends of Sockeye Salmon at the northern edge of their distribution
Michael P. Carey, Christian E. Zimmerman, Kevin D. Keith, Merlyn Schelske, Charles Lean, David C. Douglas
2017, Transactions of the American Fisheries Society (146) 791-802
Climate change is affecting arctic and subarctic ecosystems, and anadromous fish such as Pacific salmon Oncorhynchus spp. are particularly susceptible due to the physiological challenge of spawning migrations. Predicting how migratory timing will change under Arctic warming scenarios requires an understanding of how environmental factors drive salmon migrations. Multiple mechanisms...
Nest-site selection and nest success of an Arctic-breeding passerine, Smith's Longspur, in a changing climate
Heather R. McFarland, Steve J. Kendall, Abby Powell
2017, The Condor (119) 85-97
Despite changes in shrub cover and weather patterns associated with climate change in the Arctic, little is known about the breeding requirements of most passerines tied to northern regions. We investigated the nesting biology and nest habitat characteristics of Smith's Longspurs (Calcarius pictus) in 2 study areas in the Brooks...
Duckling survival of mallards in Southland, New Zealand
Erin Garrick, Courtney L. Amundson, Phillip J. Seddon
2017, Journal of Wildlife Management (81) 858-867
The southern portion of New Zealand's South Island is a productive area for mallards (Anas platyrhynchos) despite a notable lack of permanent or semi-permanent wetlands. Most broods are reared in pastures that may or may not be flooded with ephemeral water. In recent years, there has been an increased conversion...