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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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Nerodia clarkii (Saltmarsh Watersnake). Predation Nerodia clarkii (Saltmarsh Watersnake). Predation

Predators of Nerodia clarkii are suspected to include larger species of crabs, fish, wading birds, snakes, alligators, and crocodiles. To our knowledge, there have only been two published observations of predation on N. clarkii, including a predation attempt from a Callinectes sapidus (Blue Crab) in Mississippi, USA and a successful predation by a Grus americana (Whooping Crane) in Texas...
Authors
Bryna L. Daykin, Sidney T. Godfrey, Michael Cherkiss, Gareth Blakemore, Frank J. Mazzotti

Characterizing vegetation and return periods in avalanche paths using lidar and aerial imagery Characterizing vegetation and return periods in avalanche paths using lidar and aerial imagery

Snow avalanches are a hazard and ecological disturbance across mountain landscapes worldwide. Understanding how avalanche frequency affects forests and vegetation improves infrastructure planning, risk management, and avalanche forecasting. We implemented a novel approach using lidar, aerial imagery, and a random forest model to classify imagery-observed vegetation within avalanche paths...
Authors
Erich H. Peitzsch, Chelsea Martin-Mikle, Jordy Hendrikx, Karl W. Birkeland, Daniel B. Fagre

The incredible HALK: borrowing data for age assignment The incredible HALK: borrowing data for age assignment

Understanding age and growth are important for fisheries science and management; however, age data are not routinely collected for many populations. We propose and test a method of borrowing age–length data across increasingly broader spatiotemporal levels to create a hierarchical age–length key (HALK). We assessed this method by comparing growth and mortality metrics to those estimated...
Authors
Paul N. Frater, Zachary S. Feiner, Gretchen J.A. Hansen, Daniel A. Isermann, Alexander W. Latzka, Olaf P. Jensen

Sea turtle density surface models along the United States Atlantic coast Sea turtle density surface models along the United States Atlantic coast

Spatially explicit estimates of marine species distribution and abundance are required to quantify potential impacts from human activities such as military training and testing, fisheries interactions, and offshore energy development. There are 4 protected species of sea turtle (loggerhead, green, Kemp’s ridley, and leatherback) commonly found along the east coast of the USA, our study...
Authors
Andrew DiMatteo, Jason J. Roberts, D. Todd Jones-Farrand, Lance Garrison, Kristen Hart, Robert D. Kenney, William A. McLellan, Kate Lomac-MacNair, Debra Palka, Meghan E. Rickard, Kelsey E. Roberts, Ann M. Zoidis, L. Sparks

Bird-habitat associations and local-scale vegetation structure in lowland brushlands Bird-habitat associations and local-scale vegetation structure in lowland brushlands

Brushlands support a diverse suite of bird species, including species of conservation concern in the western Great Lakes region of central North America. Information on how to effectively manage lowland brushlands for birds and associations between breeding birds and local-scale vegetation structure and composition is lacking. We surveyed lowland brushlands from 2016–2018 in Minnesota...
Authors
Annie J Hawkinson, Rebecca A. Montgomery, Charlotte L. Roy, Lindsey M. Shartell, David E. Andersen, Thomas K. Stevens, Lori J. Knosalla, Lee E. Frelich

Quaternary-active faults and the role of inherited structures in the Sacramento-San Joaquin Delta, western Central Valley, northern California Quaternary-active faults and the role of inherited structures in the Sacramento-San Joaquin Delta, western Central Valley, northern California

Seismic sources and their associated hazards within the Sacramento-San Joaquin Delta region of north-central California are relatively poorly characterized as compared to other, more heavily studied regions of northern California, such as the San Francisco Bay Area. Here we present a synthesis of subsurface, bedrock geology, and geodetic datasets from the Delta and from the Coast Ranges...
Authors
Charles Cashman Trexler, Jack Willard, Belle E. Philibosian

Influence of inherited structure on flexural extension in foreland basin systems: Evidence from the northern Arkoma basin and southern Ozark dome, USA Influence of inherited structure on flexural extension in foreland basin systems: Evidence from the northern Arkoma basin and southern Ozark dome, USA

Extensional faults are key components of foreland basin systems. They form within the upper crust in response to flexure of the lithosphere and accommodate subsidence within the foredeep and forebulge depozones. Such faults are excellent proxies for orogenic system evolution and control the distribution of natural resources and hazards. However, the spatiotemporal evolution of flexural...
Authors
Brandon Michael Lutz, Mark R. Hudson, Tyson Michael Smith, Marieke Dechesne, Leland R. Spangler, Anne E. McCafferty, Chelsea Morgan Amaral, Neil Patrick Griffis, Jaime Ann Megumi Hirtz

The 2023 US National Seismic Hazard Model: Ground-motion characterization for the conterminous United States The 2023 US National Seismic Hazard Model: Ground-motion characterization for the conterminous United States

We update the ground-motion characterization for the 2023 National Seismic Hazard Model (NSHM) for the conterminous United States. The update includes the use of new ground-motion models (GMMs) in the Cascadia subduction zone; an adjustment to the central and eastern United States (CEUS) GMMs to reduce misfits with observed data; an updated boundary for the application of GMMs for...
Authors
Morgan P. Moschetti, Brad T. Aagaard, Sean Kamran Ahdi, Jason M. Altekruse, Oliver S. Boyd, Arthur D. Frankel, Julie A. Herrick, Mark D. Petersen, Peter M. Powers, Sanaz Rezaeian, Allison Shumway, James Andrew Smith, William J. Stephenson, Eric M. Thompson, Kyle Withers

Allochthonous marsh subsidies enhances food web productivity in an estuary and its surrounding ecosystem mosaic Allochthonous marsh subsidies enhances food web productivity in an estuary and its surrounding ecosystem mosaic

Terrestrial organic matter is believed to play an important role in promoting resilient estuarine food webs, but the inherent interconnectivity of estuarine systems often obscures the origins and importance of these terrestrial inputs. To determine the relative contributions of terrestrial (allochthonous) and aquatic (autochthonous) organic matter to the estuarine food web, we analyzed...
Authors
Melanie J. Davis, Isa Woo, Susan E.W. De La Cruz, Christopher S. Ellings, Sayre Hodgson, Glynnis Nakai

Examining the connections between earthquake swarms, crustal fluids, and large earthquakes in the context of the 2020-2024 Noto Peninsula, Japan, earthquake sequence Examining the connections between earthquake swarms, crustal fluids, and large earthquakes in the context of the 2020-2024 Noto Peninsula, Japan, earthquake sequence

Earthquake swarms are most commonly composed of small-magnitude earthquakes – those that may in some cases be felt but without causing damage. However, a recent study by Yoshida et al. (2023, https://doi.org/10.1029/2023GL106023) analyzed a swarm beneath the Noto Peninsula in Japan that, after more than two years of moderate-magnitude seismicity, triggered the moment magnitude (Mw) 6.2...
Authors
David R. Shelly

Physics-based satellite-derived bathymetry (SDB) using Landsat OLI images Physics-based satellite-derived bathymetry (SDB) using Landsat OLI images

The estimation of depth in optically shallow waters using satellite imagery can be efficient and cost-effective. Active sensors measure the distance traveled by an emitted laser pulse propagating through the water with high precision and accuracy if the bottom peak intensity of the waveform is greater than the noise level. However, passive optical imaging of optically shallow water...
Authors
Minsu Kim, Jeffrey J. Danielson, Curt D. Storlazzi, Seonkyung Park

Wildfire probability estimated from recent climate and fine fuels across the big sagebrush region Wildfire probability estimated from recent climate and fine fuels across the big sagebrush region

Background Wildfire is a major proximate cause of historical and ongoing losses of intact big sagebrush (Artemisia tridentata Nutt.) plant communities and declines in sagebrush obligate wildlife species. In recent decades, fire return intervals have shortened and area burned has increased in some areas, and habitat degradation is occurring where post-fire re-establishment of sagebrush is...
Authors
Martin C. Holdrege, Daniel Rodolphe Schlaepfer, Kyle A. Palmquist, Michele R. Crist, Kevin E. Doherty, William K. Lauenroth, Thomas E. Remington, Karin L. Riley, Karen C. Short, John C. Tull, Lief A. Wiechman, John B. Bradford
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