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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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Seismic moment and local magnitude scales in Ridgecrest, CA from the SCEC/USGS Community Stress Drop Validation Study Seismic moment and local magnitude scales in Ridgecrest, CA from the SCEC/USGS Community Stress Drop Validation Study

We illustrate the systematic difference between moment magnitude and local magnitude caused by underlying earthquake source physics, using seismic moments submitted to the Statewide California Earthquake Center/United States Geological Survey Community Stress Drop Validation Study 2019 Ridgecrest data set. While the relationship between seismic moment and moment magnitude ( M or Mw) of...
Authors
Annemarie S. Baltay Sundstrom, Rachel E. Abercrombie

Lead exposure in waterfowl before contoxic shot requirements: A nationwide study, 1983−1986 Lead exposure in waterfowl before contoxic shot requirements: A nationwide study, 1983−1986

Before implementing nontoxic shot requirements for hunting waterfowl and American coots Fulica americana in the United States in 1991, the U.S. Fish and Wildlife Service monitored lead poisoning in waterfowl on federal and state wildlife hunting areas during 1983-1986. Federal and state collaborators collected gizzards and livers from 9,029 hunter-killed waterfowl (10 species of dabbling...
Authors
J. Christian Franson, Christine M. Bunck

Acute heat stress and the extirpation of a threatened coral species from a remote, subtropical reef system Acute heat stress and the extirpation of a threatened coral species from a remote, subtropical reef system

The ecological significance of the reef-building elkhorn coral, Acropora palmata, is threatened by heat-stress-induced mortality. The intensity and duration of the ocean heatwave affecting Dry Tortugas National Park in the summer of 2023 was historically unprecedented in its early timing and maximum temperatures reached and resulted in 100% A. palmata mortality. To understand the...
Authors
Ava Madeline Thompson, Anastasios Stathakopoulos, Karli J. Hollister, Amelia M. Lynch, Jordan C. Holder, Ilsa B. Kuffner

Solution-collapse breccia pipe uranium deposits of the southern Colorado Plateau, northwestern Arizona, USA Solution-collapse breccia pipe uranium deposits of the southern Colorado Plateau, northwestern Arizona, USA

Some of the highest-grade uranium deposits in the United States occur in breccia pipes that formed by solution and collapse of sedimentary strata, which occur in the southern portion of the Colorado Plateau in northwestern Arizona. The host breccia pipes are up to 1200 m in vertical extent, average about 90 m in diameter, and can cross-cut strata from their base in the Mississippian...
Authors
Bradley S. Van Gosen, Susan Hall, Craig A. Johnson, William Benzel

A quantitative classification of the geography of non-native flora in the United States A quantitative classification of the geography of non-native flora in the United States

Aim Non-native plants have the potential to harm ecosystems. Harm is classically related to their distribution and abundance, but this geographical information is often unknown. Here, we assess geographical commonness as a potential indicator of invasive status for non-native flora in the United States. Geographical commonness could inform invasion risk assessments across species and...
Authors
Bethany A. Bradley, Annette Evans, Helen Sofaer, Montserrat Vilà, David Barnett, Evelyn M. Beaury, Dana M. Blumenthal, Jeffrey Corbin, Jeffrey Dukes, Regan Early, Ines Ibanez, Ian S. Pearse, Lais Petri, Cascade J.B. Sorte

Tapwater exposures, residential risk, and mitigation in a PFAS-impacted-groundwater community Tapwater exposures, residential risk, and mitigation in a PFAS-impacted-groundwater community

Tapwater (TW) safety and sustainability are priorities in the United States. Per/polyfluoroalkyl substance(s) (PFAS) contamination is a growing public-health concern due to prolific use, widespread TW exposures, and mounting human-health concerns. Historically-rural, actively-urbanizing communities that rely on surficial-aquifer private wells incur elevated risks of unrecognized TW...
Authors
Paul M. Bradley, Kristin M. Romanok, Kelly Smalling, Lee Donahue, Mark P. Gaikowski, Randy K. Hines, Sara E. Breitmeyer, Stephanie E. Gordon, Keith A. Loftin, R. Blaine McCleskey, Shannon M. Meppelink, Molly L. Schreiner

Ecological thresholds and transformations due to climate change: The role of abiotic stress Ecological thresholds and transformations due to climate change: The role of abiotic stress

An ecological threshold is the point at which a comparatively small environmental change triggers an abrupt and disproportionately large ecological response. In the face of accelerating climate change, there is concern that abrupt ecosystem transformations will become more widespread as critical ecological thresholds are crossed. There has been ongoing debate, however, regarding the...
Authors
Michael Osland, John B. Bradford, Lauren T. Toth, Matthew J. Germino, James Grace, Judith Z. Drexler, Camille L. Stagg, Eric E. Grossman, Karen M. Thorne, Stephanie Romanach, Davina Passeri, Gregory E. Noe, Jessica R. Lacy, Ken Krauss, Kurt P. Kowalski, Glenn R. Guntenspergen, Neil K. Ganju, Nicholas Enwright, Joel A. Carr, Kristin B. Byrd, Kevin J. Buffington

River floods under wetter antecedent conditions deliver coarser sediment to the coast River floods under wetter antecedent conditions deliver coarser sediment to the coast

Increasing hydrologic volatility—more extreme rain, and larger variations between wet and dry years—has become apparent in some regions, but few data exist to determine how intensifying hydrologic extremes affect sedimentary systems. Using uniquely high-resolution records of fluvial suspended sediment and coastal morphology, we quantify sedimentary responses from a steep, 357-km2...
Authors
Amy E. East, Alexander G. Snyder, Andrew W. Stevens, Jonathan A. Warrick, David J. Topping, Matthew A. Thomas, Andrew C. Ritchie

Transcriptomics as an early warning of domoic acid exposure in Pacific razor clams (Siliqua patula) Transcriptomics as an early warning of domoic acid exposure in Pacific razor clams (Siliqua patula)

As oceans warm, harmful algal blooms (HABs) are expected to increase, including blooms of Pseudo-nitzschia, a diatom that produces domoic acid (DA), which is a potent neurotoxin. Regulatory limits for human consumption (0.075–0.1 mg/kg/day; acute exposure) exist for the Pacific razor clam; however, fisheries currently do not have regulatory limits for chronic low-level exposure to DA...
Authors
Lizabeth Bowen, Shannon C. Waters-Dynes, Brenda Ballachey, Heather Coletti, Zachary Forster, Ji Li, Bradley Jenner

Detection of Giardia and Cryptosporidium in surface water of a subarctic city Detection of Giardia and Cryptosporidium in surface water of a subarctic city

Giardia and Cryptosporidium spp. are globally distributed protozoan parasites that can cause gastrointestinal disease in humans and animals. These zoonotic parasites and their ecological relationships have been understudied in Alaska and elsewhere, despite being identified as priority zoonotic pathogens. We aimed to detect and characterize Giardia and Cryptosporidium spp. in waterbodies...
Authors
Christina Ahlstrom, Michael P. Carey, Damian M. Menning, Jonathan A. O’Donnell, Andrew M. Ramey

Development of a genotyping-in-thousands by sequencing (GT-seq) panel for identifying individuals and estimating relatedness among Alaska black bears (Ursus americanus) Development of a genotyping-in-thousands by sequencing (GT-seq) panel for identifying individuals and estimating relatedness among Alaska black bears (Ursus americanus)

The management and conservation of large mammals, such as black bears (Ursus americanus), have long been informed by genetic estimates of population size and individual dispersal. Amplicon sequencing methods, also known as ‘genotyping-in-thousands-by sequencing’ (GT-seq), now enable the efficient and cost-effective genotyping of hundreds of loci and individuals in the same sequencing run...
Authors
Eleni Leto Petrou, Colette D. Brandt, Timothy J. Spivey, Kristen M. Gruenthal, Cherie Marie Mckeeman, Sean D. Farley, David Battle, Cory Stantorf, Andrew M. Ramey

Ten quick tips to get you started with Bayesian statistics Ten quick tips to get you started with Bayesian statistics

No abstract available.
Authors
Olivier Gimenez, J. Andrew Royle, Marc Kéry, Chloé Nater
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