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Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

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A Robot Operating System (ROS) package for mapping flow fields in rivers via Particle Image Velocimetry (PIV)

Non-contact, remote sensing approaches to measuring flow velocities in river channels are widely used, but typical workflows involve acquiring images in the field and then processing data later in the office. To reduce latency between acquisition and output, with the ultimate goal of enabling real-time image velocimetry, we developed a Robot Operating System (ROS) package for Particle Image Veloci
Authors
Carl J. Legleiter, Michael Dille

Cross-scale analysis reveals interacting predictors of annual and perennial cover in Northern Great Basin rangelands

Exotic annual grass invasion is a widespread threat to the integrity of sagebrush ecosystems in Western North America. Although many predictors of annual grass prevalence and native perennial vegetation have been identified, there remains substantial uncertainty about how regional-scale and local-scale predictors interact to determine vegetation heterogeneity, and how associations between vegetati
Authors
Madelon Florence Case, Kirk W. Davies, Chad S. Boyd, Lina Aoyama, Joanna Merson, Calvin Penkauskas, Lauren M. Hallett

Design and calibration of a nitrate decision support tool for groundwater wells in Wisconsin, USA

This paper describes development of a nitrate decision support tool for groundwater wells (GW-NDST) that combines nitrate leaching and groundwater lag-times to compute well concentrations. The GW-NDST uses output from support models that simulate leached nitrate, groundwater age distributions, and nitrate reduction rates. The support models are linked through convolution to simulate nitrate transp
Authors
Paul F. Juckem, Nicholas Corson-Dosch, Laura A. Schachter, Christopher Green, Kelsie M. Ferin, Eric G. Booth, Christopher J. Kucharik, Brian P. Austin, Leon J. Kauffman

Simulating past and future fire impacts on Mediterranean ecosystems

Worldwide, large wildfires are becoming increasingly common, leading to economic damages and threatening ecosystems and human health. Under future climate change, more frequent fire disturbance may push ecosystems into non-forested alternative stable states. Fire-prone ecosystems such as those in the Mediterranean Basin are expected to be particularly vulnerable, but the position of tipping points
Authors
Christoph Schwörer, César Morales-Molino, Erika Gobet, Paul D. Henne, Salvatore Pasta, Tiziana Pedrotta, Jacqueline F. N. van Leeuwen, Boris Vannière, Willy Tinner

The roles of diet and habitat use in pesticide bioaccumulation by juvenile Chinook Salmon: Insights from stable isotopes and fatty acid biomarkers

Stable isotopes (SI) and fatty acid (FA) biomarkers can provide insights regarding trophic pathways and habitats associated with contaminant bioaccumulation. We assessed relationships between SI and FA biomarkers and published data on concentrations of two pesticides [dichlorodiphenyltrichloroethane and degradation products (DDX) and bifenthrin] in juvenile Chinook Salmon (Oncorhynchus tshawytscha
Authors
Sara E. Anzalone, Neil W. Fuller, Kara E. Huff Hartz, Gregory W. Whitledge, Jason Tyler Magnuson, Daniel Schlenk, Shawn Acuña, Matt R. Whiles, Michael J. Lydy

Clumped isotopes record a glacial-interglacial shift in seasonality of soil carbonate accumulation in the San Luis Valley, southern Rocky Mountains, USA

Clumped isotope paleothermometry using pedogenic carbonates is a powerful tool for investigating past climate changes. However, location-specific seasonal patterns of precipitation and soil moisture cause systematic biases in the temperatures they record, hampering comparison of data across large areas or differing climate states. To account for biases, more systematic studies of carbonate forming
Authors
Adam M. Hudson, Julia R. Kelson, James B. Paces, Chester A. Ruleman, Katharine W. Huntington, Andrew J. Schauer

Potential impacts of an autumn oil spill on polar bears summering on land in northern Alaska

Demand for oil and natural gas continues to increase, leading to the development of remote regions where it is riskier to operate. Many of these regions have had limited development, so understanding potential impacts to wildlife could inform management decisions. In 2017, the United States passed legislation allowing oil and gas development in the coastal plain of the Arctic National Wildlife Ref
Authors
Ryan H. Wilson, Deborah French-Mckay, Craig J Perham, Susannah P Woodruff, Todd C. Atwood, George M. Durner

Timing and source of recharge to the Columbia River Basalt groundwater system in northeastern Oregon

Recharge to and flow within the Columbia River Basalt Group (CRBG) groundwater flow system of northeastern Oregon were characterized using isotopic, gas, and age-tracer samples from wells completed in basalt, springs, and stream base flow. Most groundwater samples were late-Pleistocene to early-Holocene; median age of well samples was 11,100 years. The relation between mean groundwater age and com
Authors
Henry M. Johnson, Kate E. Ely, Anna-Turi Maher

Genetic Connectivity in the Arizona toad (Anaxyrus microscaphus): implications for conservation of a stream dwelling amphibian in the arid Southwestern U.S.

The Arizona Toad (Anaxyrus microscaphus) is restricted to riverine corridors and adjacent uplands in the arid southwestern United States. As with numerous amphibians worldwide, populations are declining and face various known or suspected threats, from disease to habitat modification resulting from climate change. The Arizona Toad has been petitioned to be listed under the U.S. Endangered Species
Authors
Sara J. Oyler-McCance, Mason J. Ryan, Brian K. Sullivan, Jennifer A. Fike, Robert S. Cornman, J. T. Giermakowski, Shawna J Zimmerman, R. L. Harrow, S.J. Hedwell, Blake R. Hossack, I. M. Latella, R. E. Lovish, S. Siefken, Brent H. Sigafus, Erin L. Muths

How diverse is the toolbox? A review of management actions to conserve or restore coregonines

Over the past centuries, coregonines have been exposed to a range of stressors that have led to extinctions, extirpations, and speciation reversals. Given that some populations remain at risk and fishery managers have begun restoring coregonines where they have been extirpated, we reviewed the primary and gray literature to describe the diversity of coregonine restoration or conservation actions t
Authors
David Bunnell, Orlane Anneville, Jan Baer, Colin Bean, Kimmo Kahlilainen, Alfred Sandstrom, Oliver Selz, Pascal Vonlanthen, Josef Wanzenbock, Brian C. Weidel

Paleogene sedimentary basin development in southern Nevada, USA

The cause of the transition from Mesozoic and early Cenozoic crustal shortening to later extension in the western United States is debated. In many parts of the extant Sevier hinterland, now the Basin and Range Province, the sedimentary sections that provide the most direct record of that transition remain poorly studied and lack meaningful age control. In this paper, we present field characteriza
Authors
Jens-Erik Lundstern, Theresa Maude Schwartz, Cameron Mark Mercer, Joseph Colgan, Jeremiah B. Workman, Leah E. Morgan

Performance-based earthquake early warning for tall buildings

The ShakeAlert Earthquake Early Warning (EEW) system aims to issue an advance warning to residents on the West Coast of the United States seconds before the ground shaking arrives, if the expected ground shaking exceeds a certain threshold. However, residents in tall buildings may experience much greater motion due to the dynamic response of the buildings. Therefore, there is an ongoing effort to
Authors
S. Farid Ghahari, Khachik Sargsyan, Grace Alexandra Parker, Dan Swensen, Mehmet Çelebi, Hamid Haddadi, Ertugrul Taciroglu