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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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Modeling climate and hydropower influences on the movement decisions of an anadromous species Modeling climate and hydropower influences on the movement decisions of an anadromous species

In large river basins, migratory fish populations are threatened by the combination of hydropower and climate change. With river temperatures rising and hydropower development increasing globally, the longstanding monitoring programs for threatened Pacific salmon populations in the Columbia River Basin present an opportunity to study these impacts over extended time scales. We fit a...
Authors
Markus A. Min, Rebecca A. Buchanan, Mark David Scheuerell

Hatchery rearing density affects poststocking survival Hatchery rearing density affects poststocking survival

Objective Research has indicated that salmonids raised in a hatchery and stocked into the wild have lower future survival and reproductive success than wild fish. Understanding whether hatchery rearing practices affect populations after stocking can help to maximize the quality, quantity, and economic value of fish stocked for conservation and recreational purposes. The goal of our study...
Authors
Brian W. Avila, Dana L. Winkelman, Eric R. Fetherman

Planning considerations related to contamination control for the return and analysis of Martian samples Planning considerations related to contamination control for the return and analysis of Martian samples

The joint National Aeronautics and Space Administration and European Space Agency Mars Sample Return (MSR) Campaign is a proposed multi-mission effort to bring selected geological samples from Mars to Earth for the purpose of scientific investigation. Significant parts of these investigations could be affected by Earth-sourced contamination that is either misinterpreted as having a...
Authors
Alex L. Sessions, Cara Magnabosco, Hazel A. Barton, Christoph Burkhardt, Caroline Freissinet, Katherine L. French, Jason P. Dworkin, Daniel P. Glavin, Natalie Leys, Frank Maixner, Karen Olsson-Francis, Alexander J. Probst, Ghylaine Quitté, Elizabeth B. Rampe, Andrew Steele, Brandi L. Carrier, Lindsay E. Hays, Fiona Thiessen, Daniel Paardekooper, Aurore Hutzler, Andrea D. Harrington, Bronwyn L. Teece

Widespread anhydrite saturation in Laramide-age arc magmas of southwestern USA Widespread anhydrite saturation in Laramide-age arc magmas of southwestern USA

Anhydrite is considered a rare mineral phase in magmas, with only ∼33 documented occurrences worldwide. However, anhydrite readily decomposes in the near-surface environment, making it difficult to recognize its former presence in rocks collected at or near Earth’s surface. In such samples, only small anhydrite inclusions fully shielded within other minerals can have survived. During a...
Authors
Andreas Audétat, Jia Chang, Sean Patrick Gaynor

Magma fragmentation and tephra deposition from a small-volume phreatomagmatic eruption: Blue Lake crater, Oregon, USA Magma fragmentation and tephra deposition from a small-volume phreatomagmatic eruption: Blue Lake crater, Oregon, USA

Maars pose considerable hazards due to their more explosive nature (compared with more common scoria cones) and likelihood that eruptions produce pyroclastic surges. Blue Lake crater is a maar in the Oregon High Cascades that erupted within the last 3000 years, making it one of the youngest eruptions in the Oregon Cascades. Its young, unaltered deposits make it an excellent site to...
Authors
Sophia Leiter, Pierre-Simon Ross, Emily Renee Johnson

UAS and high-resolution satellite imagery improve the accuracy of cheatgrass detection across an invaded Yellowstone landscape UAS and high-resolution satellite imagery improve the accuracy of cheatgrass detection across an invaded Yellowstone landscape

Context Cheatgrass (Bromus tectorum L.) is a problem across the western United States, where it outcompetes and replaces native grass species, alters habitats, and increases the risk of wildfires. Cheatgrass greens up earlier in the growing season compared to native grasses, making it classifiable with multi-temporal and multi-spectral remote sensing. Objectives We mapped cheatgrass at...
Authors
Jason R. Kreitler, Joshua W. von Nonn, Seth M. Munson, Alex C. Zaideman, Steven T. Bekedam, Ann Rodman, Miguel L. Villarreal

Mechanisms influencing thermal refuges and territory occupancy by collared pikas during summer and winter Mechanisms influencing thermal refuges and territory occupancy by collared pikas during summer and winter

Collared pikas (Ochotona collaris) are cold adapted alpine lagomorphs of western Canada and Alaska, USA, that are vulnerable to direct and indirect effects of climate change. However, how and to what extent such changes influence persistence for this species is not well understood, particularly at fine spatial scales. Our goal was to evaluate how microclimate and microhabitat...
Authors
Lillian A. Harrison, Katherine S. Christie, Collette Brandt, Matthew Richard Falcy, Sophie L. Gilbert, Janet L. Rachlow

Monitoring Pacific walrus coastal haulouts by satellite to estimate herd abundance and distribution Monitoring Pacific walrus coastal haulouts by satellite to estimate herd abundance and distribution

The Pacific walrus (Odobenus rosmarus divergens) has a single, panmictic stock that ranges across the Bering and Chukchi Seas. However, its seasonal distribution is incompletely described, particularly in autumn when herds gather on shore, and abundance is of interest to management entities. We monitored walrus herds using satellite imagery on shore across their summer and autumn range...
Authors
Anthony S. Fischbach, Rebecca L. Taylor, David C. Douglas

Late Pleistocene kinematics of the Great Southern Puerto Rico Fault Zone, Puerto Rico Late Pleistocene kinematics of the Great Southern Puerto Rico Fault Zone, Puerto Rico

Several onshore faults in southern Puerto Rico have recently been recognized as Quaternary active. However, the kinematics of these faults, particularly any lateral component, remain largely unconstrained. It is difficult to characterize low strain‐rate faults, partially due to extensive erosional and anthropogenic landscape modification, steep relief, and frequent landsliding, limiting...
Authors
Emerson Madelyn Lynch, Jessica A. Thompson Jobe, Richard W. Briggs, M. Morow Tan, Victor Ortega Díaz, K. Stephen Hughes

Thirty years of the U.S. National Land Cover Database: Impacts and future direction Thirty years of the U.S. National Land Cover Database: Impacts and future direction

The National Land Cover Database (NLCD), developed through the Multi-Resolution Land Characteristics Consortium, was initiated 30 years ago and has continually provided critical, Landsat-based landcover and land-change information for the United States. Originally launched to address the lack of national-scale, moderate-resolution land-cover data, NLCD has evolved from the pioneering...
Authors
Terry L. Sohl, Suming Jin, Jon Dewitz, James Wickham, Jesslyn F. Brown, Stephen Stehman, Nathaniel Herold, Karen Schleeweis, Heather J. Tollerud, Carol Deering

Module 4: Basic biology of wetland animals Module 4: Basic biology of wetland animals

An assortment of animals inhabit wetlands, with many invertebrates, amphibians and reptiles, fishes, birds, and some mammals being wetland specialists. Wetlands provide ample water, food, and cover that benefits resident animals, but periodic high floods, frequent drying, and harsh water qualities (low-oxygen, acidic, saline) can stress wetland animals. Animals that rely on wetlands have...
Authors
Darold Batzer, Lora L. Smith, Joshua D. Stafford, Violet Harrison-Day, Samuel R. Kucia, William J. Severud, Youzheng Zhang
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