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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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Sources of yearly variation in gray bat activity in the Clinch River watershed, Virginia Sources of yearly variation in gray bat activity in the Clinch River watershed, Virginia

The gray bat (Myotis grisescens) is a cave-obligate species that has been listed as federally endangered since 1976, following population declines from human disturbance at hibernation and maternity caves. However, with cave protection, most gray bat populations have increased. As part of a project examining bat use of transportation structures as day-roosts, we continuously acoustically...
Authors
H. Taylor, K. Powers, W. Orndorff, Rick Reynolds, E. M. Hallerman, W. Mark Ford

Years of magma intrusion primed Kīlauea Volcano (Hawai'i) for the 2018 eruption: Evidence from olivine diffusion chronometry and monitoring data Years of magma intrusion primed Kīlauea Volcano (Hawai'i) for the 2018 eruption: Evidence from olivine diffusion chronometry and monitoring data

The mechanisms that led to the exceptionally large Kīlauea 2018 eruption are still poorly understood and actively debated. External processes such as rainfall events or flank sliding have been proposed to play a triggering role. Here, we present field, geophysical, and petrological observations to show that internal changes within the magmatic plumbing system most likely led to the...
Authors
Adrien J. Mourey, Tom Shea, Fidel Costa, Brian Shiro, Ryan J. Longman

Patterns of zero and nonzero counts suggest spatiotemporal distributions, aggregation, and dispersion of invasive carp Patterns of zero and nonzero counts suggest spatiotemporal distributions, aggregation, and dispersion of invasive carp

Bigheaded carp Hypophthalmichthys spp. are invasive species native to Asia expanding in the Mississippi River Basin in North America. An understanding of spatiotemporal distribution and aggregation of invasive carp is key to establishing when and where to focus surveillance designed to monitor expansion, and to managing harvest programs designed to curb population densities. We applied a...
Authors
Leandro E. Miranda, J. Tompkins, Corey Garland Dunn, J. L. Morris, Matthew C. Combs

Insights into the metamorphic history and origin of flake graphite mineralization at the Graphite Creek graphite deposit, Seward Peninsula, Alaska, USA Insights into the metamorphic history and origin of flake graphite mineralization at the Graphite Creek graphite deposit, Seward Peninsula, Alaska, USA

Graphite Creek is an unusual flake graphite deposit located on the Seward Peninsula, Alaska, USA. We present field observations, uranium-lead (U–Pb) monazite and titanite geochronology, carbon (C) and sulfur (S) stable isotope geochemistry, and graphite Raman spectroscopy data from this deposit that support a new model of flake graphite ore genesis in high-grade metamorphic environments...
Authors
George N.D. Case, Susan M. Karl, Sean P. Regan, Craig A. Johnson, Eric T Ellison, Jonathan Saul Caine, Christopher S. Holm-Denoma, Laura S. Pianowski, Jeff A. Benowitz

Laboratory and field comparisons of TFM bar formulations used to treat small streams for larval sea lamprey Laboratory and field comparisons of TFM bar formulations used to treat small streams for larval sea lamprey

A solid formulation of the pesticide TFM (4-nitro-3-(trifluoromethyl)-phenol) was developed in the 1980s for application in small tributaries during treatments to control invasive sea lamprey (Petromyzon marinus Linnaeus, 1758). Several initial inert ingredients were discontinued and substituted, culminating with an interim formulation that unacceptably softens and rapidly decays in warm...
Authors
James A. Luoma, Justin R. Schueller, Nicholas Schloesser, Todd Johnson, Courtney A. Kirkeeng

Estimates of volcanic mercury emissions from Redoubt Volcano, Augustine Volcano, and Mount Spurr eruption ash Estimates of volcanic mercury emissions from Redoubt Volcano, Augustine Volcano, and Mount Spurr eruption ash

Ash is a potential sink of volcanically sourced atmospheric mercury (Hg), and the concentration of particle-bound Hg may provide constraints on Hg emissions during eruptions. We analyze Hg concentrations in 227 bulk ash samples from the Mount Spurr (1992), Redoubt Volcano (2009), and Augustine Volcano (2006) volcanic eruptions to investigate large-scale spatial, temporal, and volcanic...
Authors
D Skye Kushner, Taryn Lopez, Kristi L. Wallace, David Damby, Christoph Kern, Cheryl Cameron

Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian

Quantifying how contaminants change across life cycles of species that undergo metamorphosis is critical to assessing organismal risk, particularly for consumers. Pond-breeding amphibians can dominate aquatic animal biomass as larvae and are terrestrial prey as juveniles and adults. Thus, amphibians can be vectors of mercury exposure in both aquatic and terrestrial food webs. However, it...
Authors
Freya Elizabeth Rowland, Erin L. Muths, Collin A. Eagles-Smith, Craig A. Stricker, Johanna M. Kraus, Rachel A. Harrington, David M. Walters

Climate change as a global amplifier of human–wildlife conflict Climate change as a global amplifier of human–wildlife conflict

Climate change and human–wildlife conflict are both pressing challenges for biodiversity conservation and human well-being in the Anthropocene. Climate change is a critical yet underappreciated amplifier of human–wildlife conflict, as it exacerbates resource scarcity, alters human and animal behaviours and distributions, and increases human–wildlife encounters. We synthesize evidence of...
Authors
Briana Abrahms, Neil H. Carter, T.J. Clark-Wolf, Kaitlyn M. Gaynor, Erik Johansson, Michael C Mcinturff, Anna Nisi, Kasim Rafiq, Leigh West

Nitrate-stimulated release of naturally occurring sedimentary uranium Nitrate-stimulated release of naturally occurring sedimentary uranium

Groundwater uranium (U) concentrations have been measured above the U.S. EPA maximum contaminant level (30 μg/L) in many U.S. aquifers, including in areas not associated with anthropogenic contamination by milling or mining. In addition to carbonate, nitrate has been correlated to uranium groundwater concentrations in two major U.S. aquifers. However, to date, direct evidence that...
Authors
Jeffrey P Westrop, Pooja Yadav, PJ Nolan, Kate M. Campbell, Rajesh Singh, Sharon Bone, Alicia Chan, Anthony Hohtz, Donald Pan, Olivia Healy, John Bargar, Daniel D. Snow, Karrie Weber

A big data–model integration approach for predicting epizootics and population recovery in a keystone species A big data–model integration approach for predicting epizootics and population recovery in a keystone species

Infectious diseases pose a significant threat to global health and biodiversity. Yet, predicting the spatiotemporal dynamics of wildlife epizootics remains challenging. Disease outbreaks result from complex nonlinear interactions among a large collection of variables that rarely adhere to the assumptions of parametric regression modeling. We adopted a nonparametric machine learning...
Authors
Gabriel M. Barrile, David J. Augustine, Lauren M. Porensky, Courtney J. Duchardt, Kevin T. Shoemaker, Cynthia R. Hartway, Justin D. Derner, Elizabeth Ann Hunter, Ana D. Davidson

Lake Erie hypoxia spatial and temporal dynamics present challenges for assessing progress toward water quality goals Lake Erie hypoxia spatial and temporal dynamics present challenges for assessing progress toward water quality goals

Seasonal hypolimnetic hypoxia has been documented in Lake Erie’s central basin since the 1950s. Ship-based surveys to monitor hypoxia have been conducted since the 1980s, but they occur at a relatively low frequency and focus on the deeper areas of the central basin. To better document the seasonal development of stratification and the consequent occurrence of hypoxia, we deployed eight...
Authors
Craig A. Stow, Mark D. Rowe, Casey M. Godwin, Lacey A. Mason, Peter Alsip, Richard Kraus, Thomas Johengen, Stephen A. Constant
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