Articles
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
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.
Filter Total Items: 78100
The U.S. Geological Survey 2025 Puerto Rico and U.S. Virgin Islands time-independent earthquake rupture forecast The U.S. Geological Survey 2025 Puerto Rico and U.S. Virgin Islands time-independent earthquake rupture forecast
We present the 2025 U.S. Geological Survey Puerto Rico and U.S. Virgin Islands (PRVI) time‐independent earthquake rupture forecast (ERF), developed for the 2025 update to the National Seismic Hazard Model (NSHM) for PRVI. The updated ERF improves upon a prior model from 2003, including an expanded fault inventory with slip‐rate estimates, updated seismicity catalogs, and refined...
Authors
Kevin Ross Milner, Alexandra Elise Hatem, Richard W. Briggs, Jessica A. Thompson Jobe, Andrea L. Llenos, Andrew J. Michael, Allison M. Shumway, Edward H. Field, Kirstie Lafon Haynie
Depositional interplay between the Ancestral Rocky Mountains and Ouachita–Marathon–Sonora orogenies: Insights from provenance records in the late Paleozoic Marfa Basin, West Texas, U.S.A. Depositional interplay between the Ancestral Rocky Mountains and Ouachita–Marathon–Sonora orogenies: Insights from provenance records in the late Paleozoic Marfa Basin, West Texas, U.S.A.
The Marfa Basin in West Texas is a late Palaeozoic synorogenic depocenter associated with regional deformation linked to the Ancestral Rocky Mountains (ARM) and Ouachita–Marathon–Sonora (OMS) orogenies in southwestern Laurentia. Basin strata range in age from Middle Pennsylvanian to the middle Permian and include the Cieneguita, Alta, Pinto Canyon, Rose Mine and Mina Grande Formations...
Authors
Sandra Juárez-Zúñiga, Daniel F. Stockli, Benjamin G. Johnson, Timothy F. Lawton
Statewide agent-based model for management of chronic wasting disease in white-tailed deer: PAOvCWD Statewide agent-based model for management of chronic wasting disease in white-tailed deer: PAOvCWD
Chronic wasting disease (CWD) is an always-fatal disease infecting wild cervids globally. Ecologically and economically important, CWD presents a challenge for managing white-tailed deer (Odocoileus virginianus). We built an agent-based model to simulate CWD transmission and assess potential management actions that could slow disease spread: PAOvCWD. We developed PAOvCWD using contact...
Authors
Nathaniel H. Wehr, Christopher S. Rosenberry, David Stainbrook, Maureen Staats, Andrea L. Korman, W. David Walter
Dog attacks on wild desert tortoises: A risk model Dog attacks on wild desert tortoises: A risk model
We retrospectively compiled a database of 6,727 live, wild Agassiz's desert tortoises (Gopherus agassizii) and evaluated them for clinical signs of trauma to shell and limbs at 50 sites in the Mojave and Colorado (western Sonoran) deserts of California, USA, spanning the years 1977–2006. Our objectives were to 1) identify tortoises with severe trauma to shell, limbs, and gular horns...
Authors
Andrea S. Carlson, Kristin H. Berry, Jeremy S. Mack
Invasion resistance varies by fuel break type in sagebrush ecosystems Invasion resistance varies by fuel break type in sagebrush ecosystems
Background Wildfire is an increasingly important driver of changes within sagebrush (Artemisia spp. L.) ecosystems of the western USA, often resulting in increased spread of exotic annual grasses, such as cheatgrass (Bromus tectorum L.), and subsequent losses of native vegetation and wildlife habitat. Fuel breaks— areas of land treated to reduce or redistribute fuel loads — are widely...
Authors
Austin L. Nash, Brianne E. Brussee, Cali L. Weise, Douglas J. Shinneman, Susan K. McIlroy, Sarah C. Webster, Steven R. Mathews, Seth J. Dettenmaier, Lea A. Condon, Michele R. Crist, Cameron L. Aldridge, Julie A. Heinrichs, Mark A. Ricca, Shawn T. O’Neil, Peter S. Coates
Stress states on the eve of past earthquakes inform earthquake rupture through fault complexity along the San Andreas and San Jacinto faults Stress states on the eve of past earthquakes inform earthquake rupture through fault complexity along the San Andreas and San Jacinto faults
Estimating the evolving state of stress along active fault systems can provide insight into the conditions that generated past ground‐rupturing earthquakes and influenced their ability to propagate through areas of geometric complexity, such as fault branches and stepovers. We use quasi‐static forward numerical models that incorporate the 3D complex configuration of active faults in...
Authors
Emery Anderson-Merritt, Michelle Cooke, Katherine M. Scharer
Optimizing cryo-focused pyrolysis GC/MS for tracing soil organic matter across diverse ecosystems Optimizing cryo-focused pyrolysis GC/MS for tracing soil organic matter across diverse ecosystems
The cycling of organic matter in terrestrial soils and sediments is central to a range of biogeochemical processes that regulate nutrient cycling, crop productivity, trace gas emissions, and contaminant transport. Pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) is a powerful tool for characterizing bulk soil organic matter (SOM) at the molecular level. In this study, we used a...
Authors
Abrar Shahriar, Mavrik Zavarin, Erin E. Nuccio, Katherine E. Grant, Karis J. McFarlane, Jennifer Pett-Ridge, David Toews, Jason P. Sexton, Rebecca Ryals, Joy Baccel, Aiden J. Berndt, Rene Boiteau, Ishtiaq Ahmed Jawad, Yu Yang, Sheel Bansal, Edward J. O’Loughlin, Kenneth M. Kemner, Roser Matamala, Keith D. Morrison
Intertidal community responses to perturbations along Alaska park coastlines Intertidal community responses to perturbations along Alaska park coastlines
Nearshore ecosystems are highly productive zones with strong connections to both terrestrial and open ocean ecosystems. The rocky intertidal is a highly dynamic ecosystem and changes over a variety of spatial and temporal scales depending on the factors contributing to the change. Here we summarize how nearshore communities and species responded to several perturbations to intertidal...
Authors
Sarah Beth Traiger, Brenda Ballachey, Heather Coletti, Daniel Esler
Investigating the role of lake environments and food chains on the transfer of mercury to lake trout Investigating the role of lake environments and food chains on the transfer of mercury to lake trout
Mercury contamination can pose threats to fish, wildlife, and people. Methylmercury, found in fish, can be particularly detrimental, especially to children. This study explores the sources and concentrations of mercury and proposes how people can become aware and limit their exposure.
Authors
Sarah M. Laske, Krista K. Bartz, Daniel Young
Cyanobacteria and aquatic ecosystem dynamics across 28,000 years of environmental changes in subtropical North America Cyanobacteria and aquatic ecosystem dynamics across 28,000 years of environmental changes in subtropical North America
Ecological pressures on aquatic ecosystems have increased over recent centuries due to human activities and climate change. However, contextualizing ecosystem deterioration is often challenging due to limited knowledge of environmental changes over millennial timescales. Subtropical Carolina bays in North Carolina, USA, have remained unglaciated, preserving paleolimnological records that...
Authors
Savvas Paradeisis-Stathis, Matthew N. Waters, Debra A. Willard, Richard S. Vachula
Evaluating drivers of environmental change in a lake sediment core: Insights from spectroscopic metrics of water-extractable organic matter and stable carbon isotopes Evaluating drivers of environmental change in a lake sediment core: Insights from spectroscopic metrics of water-extractable organic matter and stable carbon isotopes
Freshwater lakes play a critical role in the global carbon cycle by storing and transforming organic matter (OM) from both terrestrial and aquatic sources. Small lakes in northern temperate regions, despite their limited surface area, disproportionately influence regional carbon budgets. Buried sediments integrate OM inputs over time and archive ecosystem responses to natural and...
Authors
A.C. Collins, Sabina R. Gifford, Morgan Schaller, Aron Stubbins, Sasha Wagner, Kevin Alexander Ryan
Understanding the links between functional performance and environment in cold desert ecosystems through the flagship biocrust forming moss Syntrichia caninervis Understanding the links between functional performance and environment in cold desert ecosystems through the flagship biocrust forming moss Syntrichia caninervis
Background and aims Biocrust communities shape the soil surface in drylands, regulating important ecosystem properties. Despite this, few works address key functional attributes in these poikilohydric photosynthetic communities, including the length of metabolic activity in the field and its relationship with microclimate. We aim to disentangle the links between functional performance of...
Authors
Jose Raggio, David S. Pescador, Edmund E. Grote, L.G. Sancho, Rebecca A Finger-Higgens, Jayne Belnap