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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
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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Anthropogenic subsidies influence resource use during a mange epizootic in a desert coyote population Anthropogenic subsidies influence resource use during a mange epizootic in a desert coyote population
Colonization of urban areas by synanthropic wildlife introduces novel and complex alterations to established ecological processes, including the emergence and spread of infectious diseases. Aggregation at urban resources can increase disease transfer, with wide-ranging species potentially infecting outlying populations. The garrison at the National Training Center, Fort Irwin, California...
Authors
Craig D. Reddell, Gary W. Roemer, David K. Delaney, Talesha Karish, James W. Cain
A review of common natural disasters as analogs for asteroid impact effects and cascading hazards A review of common natural disasters as analogs for asteroid impact effects and cascading hazards
Modern civilization has no collective experience with possible wide-ranging effects from a medium-sized asteroid impactor. Currently, modeling efforts that predict initial effects from a meteor impact or airburst provide needed information for initial preparation and evacuation plans, but longer-term cascading hazards are not typically considered. However, more common natural disasters...
Authors
Timothy N. Titus, D. G. Robertson, Joel B. Sankey, Larry G. Mastin, Francis K. Rengers
From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence
In the long-term absence of disturbance, ecosystems often enter a decline or retrogressive phase which leads to reductions in primary productivity, plant biomass, nutrient cycling and foliar quality. However, the consequences of ecosystem retrogression for higher trophic levels such as herbivores and predators, are less clear. Using a post-fire forested island-chronosequence across which
Authors
Anne Kempel, Eric Allan, Martin M. Gossner, Malte Jochum, James Grace, David A. Wardle
Six years of fluvial response to a large dam removal on the Carmel River, California, USA Six years of fluvial response to a large dam removal on the Carmel River, California, USA
Measuring river response to dam removal affords a rare, important opportunity to study fluvial response to sediment pulses on a large field scale. We present a before–after/control–impact study of the Carmel River, California, measuring fluvial geomorphic and grain-size evolution over 8 years, six of which postdated removal of a 32 m-high dam (one of the largest dams removed worldwide)...
Authors
Amy E. East, Lee R. Harrison, Douglas P. Smith, Joshua B. Logan, Rosealea Bond
Increasing Alaskan river discharge during the cold season is driven by recent warming Increasing Alaskan river discharge during the cold season is driven by recent warming
Arctic hydrology is experiencing rapid changes including earlier snow melt, permafrost degradation, increasing active layer depth, and reduced river ice, all of which are expected to lead to changes in stream flow regimes. Recently, long-term (>60 years) climate reanalysis and river discharge observation data have become available. We utilized these data to assess long-term changes in...
Authors
D Blaskey, Joshua C. Koch, M. Gooseff, A. C. Newman, Yang Cheng, Jonathan A. O’Donnell, K Musselman
Upwelling, climate change, and the shifting geography of coral reef development Upwelling, climate change, and the shifting geography of coral reef development
The eastern tropical Pacific is oceanographically unfavorable for coral-reef development. Nevertheless, reefs have persisted there for the last 7000 years. Rates of vertical accretion during the Holocene have been similar in the strong-upwelling Gulf of Panamá (GoP) and the adjacent, weak-upwelling Gulf of Chiriquí (GoC); however, seasonal upwelling in the GoP exacerbated a climate...
Authors
Victor Rodriguez-Ruano, Lauren T. Toth, Ian C. Enochs, Carly J. Randall, Richard B. Aronson
Detection and monitoring of small-scale diamond and gold mining dredges using synthetic aperture radar on the Kadéï (Sangha) River, Central African Republic Detection and monitoring of small-scale diamond and gold mining dredges using synthetic aperture radar on the Kadéï (Sangha) River, Central African Republic
Diamond and gold mining has been practiced by artisanal miners in the Central African Republic (CAR) for decades. The recent introduction of riverine dredges indicates a transition from artisanal/manual digging and sorting techniques to small-scale mining methods. This study implements a remote sensing analysis of Synthetic Aperture Radar (SAR) data to map gold and diamond dredges...
Authors
Marissa Ann Alessi, Pete G. Chirico, Sindhuja Sunder, Kelsey L. O’Pry
Stabilising effects of karstic groundwater on stream fish communities Stabilising effects of karstic groundwater on stream fish communities
Although groundwater exchange processes are known to modulate atmospheric influences on stream temperature and flow, the implications for ecological stability are poorly understood. Here, we evaluated temporal change in stream fish communities across a gradient of groundwater influence defined by karst terrain (carbonate parent materials) within the Potomac River basin of eastern North...
Authors
Nathaniel P. Hitt, Karli M. Rogers, Karmann G. Kessler, Martin A. Briggs, Jennifer H. Fair
Sierra Nevada amphibians demonstrate stable occupancy despite precipitation volatility in the early 21st Century Sierra Nevada amphibians demonstrate stable occupancy despite precipitation volatility in the early 21st Century
Climate can have a strong influence on species distributions, and amphibians with different life histories might be affected by annual variability in precipitation in different ways. The Sierra Nevada of California, United States, experienced some of the driest and wettest years on record in the early 21st Century, with variability in annual precipitation predicted to increase with...
Authors
Brian J. Halstead, Patrick M. Kleeman, Jonathan P. Rose, Gary M. Fellers
When less is more: How increasing the complexity of machine learning strategies for geothermal energy assessments may not lead toward better estimates When less is more: How increasing the complexity of machine learning strategies for geothermal energy assessments may not lead toward better estimates
Previous moderate- and high-temperature geothermal resource assessments of the western United States utilized data-driven methods and expert decisions to estimate resource favorability. Although expert decisions can add confidence to the modeling process by ensuring reasonable models are employed, expert decisions also introduce human and, thereby, model bias. This bias can present a...
Authors
Stanley Paul Mordensky, John Lipor, Jacob DeAngelo, Erick R. Burns, Cary Ruth Lindsey
Regolith of the crater floor units, Jezero crater, Mars: Textures, composition and implications for provenance Regolith of the crater floor units, Jezero crater, Mars: Textures, composition and implications for provenance
A multi-instrument study of the regolith of Jezero crater floor units by the Perseverance rover has identified three types of regolith: fine-grained, coarse-grained, and mixed-type. Mastcam-Z, WATSON, and SuperCam RMI were used to characterize regolith texture, particle size, and roundedness where possible. Mastcam-Z multispectral and SuperCam LIBS data were used to constrain the...
Authors
Alicia Vaughan, Michelle E. Minitti, Emily L. Cardarelli, Jeffrey R. Johnson, Linda C. Kah, Paolo Pilleri, Mellisa S. Rice, Mark Sephton, Briony H. N. Horgan, Roger C. Wiens, R. Aileen Yingst, Maria-Paz Zorzano, Ryan B. Anderson, James F. III Bell, Adrian J. Brown, Edward A. Cloutis, Agnes Cousin, Kenneth E. Herkenhoff, Elisabeth M. Housrath, Alexander G. Hayes, Kjartan M. Kinch, Marco Merusi, Chase C. Million, Robert Sullivan, S. Siljeström, Michael St. Clair
Predicting habitat and distribution of an interior highlands regional endemic winter stonefly (Allocapnia mohri) in Arkansas using random forest models Predicting habitat and distribution of an interior highlands regional endemic winter stonefly (Allocapnia mohri) in Arkansas using random forest models
Stoneflies are a globally threatened aquatic insect order. In Arkansas, a diverse group of winter stonefly (Capniidae: Allocapnia) have not been surveyed since the 1980s, likely because species-level identification requires the rarely-collected adult form. Allocapnia mohri, a regional endemic, was previously commonly found in mountainous, intermittent streams from the Ouachita Mountains...
Authors
Brianna Annaratone, Camryn Larson, Clay Prater, Ashley Dowling, Daniel D. Magoulick, Michelle A. Evans-White