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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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Scattered tree death contributes to substantial forest loss in California Scattered tree death contributes to substantial forest loss in California
In recent years, large-scale tree mortality events linked to global change have occurred around the world. Current forest monitoring methods are crucial for identifying mortality hotspots, but systematic assessments of isolated or scattered dead trees over large areas are needed to reduce uncertainty on the actual extent of tree mortality. Here, we mapped individual dead trees in...
Authors
Yang Cheng, Stefan Oehmcke, Martin Brandt, Lisa Micaela Rosenthal, Adrian Das, Anton Vrieling, Sassan Saatchi, Fabien Wagner, Maurice Mugabowindekwe, Wim Verbruggen, Claus Beier, Stephanie Horion
Hybrid CPU-GPU solution to regularized divergence-free curl-curl equations for electromagnetic inversion problems Hybrid CPU-GPU solution to regularized divergence-free curl-curl equations for electromagnetic inversion problems
The Curl-Curl equation is the foundation of time-harmonic electromagnetic (EM) problems in geophysics. The efficiency of its solution is key to EM simulations, accounting for over 95% of the computation cost in geophysical inversions for magnetotelluric or controlled-source EM problems. However, most published EM inversion codes are still central processing unit (CPU)-based and cannot...
Authors
Hao Dong, Kai Sun, Gary D. Egbert, Anna Kelbert, Naser Meqbel
Novel technique for suppressing an invasive apex predator minimally alters nitrogen dynamics in Yellowstone Lake, Wyoming, USA Novel technique for suppressing an invasive apex predator minimally alters nitrogen dynamics in Yellowstone Lake, Wyoming, USA
Non-native species have invaded most ecosystems and methods are needed to manage them, especially in locations with sensitive species where they cannot be easily extirpated. Gillnetting for invasive lake trout [Salvelinus namaycush (Walbaum, 1792)] in Yellowstone Lake, Yellowstone National Park, USA began in 1995 and their carcasses are deposited into deep areas. This suppression method...
Authors
Lusha M. Tronstad, Dominique R. Lujan, Michelle A. Briggs, Lindsey K. Albertson, Hayley C. Glassic, Christopher S. Guy, Todd M. Koel
Linking avian malaria parasitemia estimates from quantitative PCR and microscopy reveals new infection patterns in Hawai'i Linking avian malaria parasitemia estimates from quantitative PCR and microscopy reveals new infection patterns in Hawai'i
Plasmodium parasites infect thousands of species and provide an exceptional system for studying host-pathogen dynamics, especially for multi-host pathogens. However, understanding these interactions requires an accurate assay of infection. Assessing Plasmodium infections using microscopy on blood smears often misses infections with low parasitemias (the fractions of cells infected), and...
Authors
Christa Seidi, Francisco C Ferreira, Katy L. Parise, Kristina L. Paxton, Eben H. Paxton, Carter T. Atkinson, Robert C. Fleischer, Jeffery T. Foster, A. Marm Kipatrick
Temporal variability in irrigated land and climate influences on salinity loading across the Upper Colorado River Basin, 1986-2017 Temporal variability in irrigated land and climate influences on salinity loading across the Upper Colorado River Basin, 1986-2017
Freshwater salinization is a growing global concern impacting human and ecosystem needs with impacts to water availability for human and ecological uses. In the Upper Colorado River Basin (UCRB), dissolved solids in streams compound ongoing water supply challenges to further limit water availability and cause economic damages. Much effort has been dedicated to understanding dissolved...
Authors
Olivia L. Miller, Annie L. Putman, Richard A. Smith, Gregory E. Schwarz, Michael D. Hess, Morgan C. McDonnell, Daniel K. Jones
Wetland geomorphology and tidal hydrodynamics drive fine-scale fish community composition and abundance Wetland geomorphology and tidal hydrodynamics drive fine-scale fish community composition and abundance
Effective restoration of tidal wetlands for fish communities requires clear goals and mechanistic understanding of the ecosystem drivers which affect fish distribution and abundance. We examined fish community responses to abiotic habitat features in two adjacent but dissimilar freshwater tidal wetlands in the Sacramento-San Joaquin Delta, CA, USA, each of which represents a potential...
Authors
Justin Kinsey Clause, Mary Jade Farruggia, Frederick V. Feyrer, Matthew J. Young
Facilitating comparable research in seedling functional ecology Facilitating comparable research in seedling functional ecology
Ecologists have worked to ascribe function to the variation found in plant populations, communities and ecosystems across environments for at least the past century. The vast body of research in functional ecology has drastically improved understanding of how individuals respond to their environment, communities are assembled and ecosystems function. However, with limited exceptions, few...
Authors
Daniel E. Winkler, Magda Garbowski, Kevin Kozic, Emma Ladouceur, Julie Larson, Sarah Martin, Christoph Rosche, Christiane Roscher, Mandy L. Slate, Lotte Korell
On-orbit calibration and performance of the EMIT imaging spectrometer On-orbit calibration and performance of the EMIT imaging spectrometer
The Earth surface Mineral dust source InvesTigation (EMIT) is a remote visible to shortwave infrared (VSWIR) imaging spectrometer that has been operating onboard the International Space Station since July 2022. This article describes EMIT's on-orbit spectroradiometric calibration and validation. Accurate spectroscopy is vital to achieve consistent mapping results with orbital imaging...
Authors
David R. Thompson, Robert O. Green, Christine Bradley, Philip G. Brodrick, Natalie Mahowald, Eyal Ben-Dor, Matthew R. Bennett, Michael Bernas, Nimrod Carmon, K. Dana Chadwick, Roger N. Clark, Red Willow Coleman, Evan Cox, Ernesto L. Diaz, Michael L. Eastwood, Regina Eckert, Bethany L. Ehlmann, Paul Ginoux, Marıa Goncalves Ageitos, Kathleen Grant, Louis Guanter, Daniela Heller Pearlshtien, Mark Helmlinger, Harrison Herzog, Todd M. Hoefen, Yue Huang, Abigail Keebler, Olga Kalashnikova, Didier Keymeulen, Raymond F. Kokaly, Martina Klose, Longlei Li, Sarah Lundeen, John Michael Meyer, Elizabeth Middleton, Ron L. Miller, Pantazis Mouroulis, Bogdan Oaida, Vicenzo Obiso, Francisco Ochoa, Winston Olson-Duvall, Gregory S. Okin, Thomas H. Painter, Carlos Perez Garcıa-Pando, Randy Pollock, Vincent J. Realmuto, Lucas Shaw, Peter Sullivan, Gregg A. Swayze, Erik Thingvold, Andrew K Thorpe, Suresh Vannan, Catalina Villarreal, Charlene Ung, Daniel W. Wilson, Sander Zandbergen
Abundance of five sympatric stream dwelling mussels varies with physical habitat Abundance of five sympatric stream dwelling mussels varies with physical habitat
Freshwater mussel species regularly co-occur in streams forming assemblages, but the extent of shared versus unique instream habitat features that contribute to their distribution and abundance is poorly understood. In Massachusetts, a rare species, Alasmidonta varicosa, is often found with four other species: Alasmidonta undulata, Strophitus undulatus, Margaritifera margaritifera, and...
Authors
Ayla J. Skorupa, Allison H. Roy, Peter D. Hazelton, David Perkins, Timothy Warren, Andy Fisk
Constraining magma storage conditions of the Toba magmatic system: A plagioclase and amphibole perspective Constraining magma storage conditions of the Toba magmatic system: A plagioclase and amphibole perspective
Silicic magma reservoirs are responsible for producing the largest explosive eruptions in the geologic record. Petrologic and geochronological data provide evidence for these systems spending substantial periods of time (104–105 yrs) within the upper crust prior to eruption; however, the long-term thermochemical evolution of these systems is not fully understood, as existing petrologic...
Authors
Jordan Edward Lubbers, Adam J.R. Kent, Shanaka de Silva
Intrinsic and extrinsic regulation of water clarity in a large, floodplain-river ecosystem Intrinsic and extrinsic regulation of water clarity in a large, floodplain-river ecosystem
Ecosystem processes in rivers are thought to be controlled more by extrinsic than intrinsic factors, that is, the result of processes that occur upstream or within their watersheds. However, large floodplain rivers have a diverse assemblage of aquatic areas spanning gradients of connectivity with the main channel and internal controls may at times regulate long-term dynamics. When and...
Authors
Alicia Carhart, Deanne C. Drake, James R. Fischer, Jeffrey N. Houser, Kathi Jo Jankowski, John E. Kalas, Eric M. Lund
The 1886 Charleston, South Carolina, earthquake: Intensities and ground motions The 1886 Charleston, South Carolina, earthquake: Intensities and ground motions
The 1 September 1886 Charleston, South Carolina, earthquake was one of the largest preinstrumental earthquakes in eastern North America for which extensive contemporaneous observations were documented. The distribution of shaking was mapped shortly after the earthquake, and reconsidered by several authors in the late twentieth century, but has not been reconsidered with a modern...
Authors
Susan E. Hough, Roger Bilham