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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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Conflicts and collisions with an endangered carnivore: Landscape drivers and spatial risk pattern Conflicts and collisions with an endangered carnivore: Landscape drivers and spatial risk pattern
Human–wildlife conflicts and anthropogenic mortality are expected to increase with the continuous encroachment on natural habitats within and around protected areas, yet the processes governing these risks remain poorly understood. We investigated the spatiotemporal dynamics and drivers of two distinct processes involving the endangered Florida panther (Puma concolor coryi; hereafter...
Authors
Marta Prat-Guitart, David P. Onorato, James E. Hines, Madan K. Oli
Non-destructive sampling of larval amphibians shows tail tissues reflect whole-body methylmercury concentrations and trophic-related differences in bioaccumulation Non-destructive sampling of larval amphibians shows tail tissues reflect whole-body methylmercury concentrations and trophic-related differences in bioaccumulation
Mercury (Hg), and specifically methylmercury (MeHg), is a contaminant of global concern to humans and wildlife, but there is still limited understanding of its effects on many taxa. Amphibians are closely associated with water, where Hg is converted to MeHg, and high concentrations of MeHg can reduce survival of amphibians in the wild. However, limited non-lethal proxies exist for...
Authors
Brian J. Tornabene, Blake Hossack, Daniel A. Grear, Thomas L. Anderson, Brad Glorioso, Hardin Waddle, Jon D Davenport, Collin Eagles-Smith, Caitlin T. Rumrill, Kelly L. Smalling
Weathering the ride: Associations of heat, smoke, precipitation, and ozone with bus ridership in Colorado Weathering the ride: Associations of heat, smoke, precipitation, and ozone with bus ridership in Colorado
Weather and climate variability increasingly shape urban travel behavior, yet the short-term temporal dynamics and contextual modifiers of weather-transit relationships remain poorly understood. We analyzed system-wide hourly bus ridership in the Denver metropolitan area from June 2022 through September 2023 using fixed-effects negative binomial distributed lag nonlinear models with lags...
Authors
Priyanka deSouza, Elizabeth A. Dzwonczyk, Peter Christian Ibsen, Adam M. Lippert, Carl Green, T.C. Chakraborty, Melissa R. McHale, Peter Anthamatten, Ebru Altintas, Carrie Makarewicz
Tectonically driven integration of the 4.8 Ma Colorado River USA tracked with detrital sanidine and fish genetics Tectonically driven integration of the 4.8 Ma Colorado River USA tracked with detrital sanidine and fish genetics
The development of the continental-scale Colorado River system, western USA, from 8 to 4.8 Ma, is revealed using 60-40 Ma detrital sanidine tracer grains and fish phylogeny. Here we show that precursor paleoriver segments became integrated north to south as traced by 60-40 Ma sand grains that were derived from the north and sequentially appeared in the 25-8 Ma Browns Park Formation of...
Authors
K. E. Karlstrom, M. Heizler, A. Aslan, Ian W. Hillenbrand, S. Cather, T. F. Turner, M. Osborne, C. D. Henry, L. J. Crossey
The digital archivist: Automating legacy macroseismic data processing using large language models The digital archivist: Automating legacy macroseismic data processing using large language models
Macroseismic data are a key resource to investigate shaking and damage from preinstrumental and early instrumental eras. However, data are often stored as inconsistently formatted reports describing observed shaking and damage, making manually parsing and interpreting accounts labor‐intensive. We introduce a novel workflow using Google’s Gemini 2.5 Pro large language model (LLM) to...
Authors
Aarnav Agrawal, Susan E. Hough, Mostafa Mousavi, Margaret Hellweg, William Ellsworth, Clara Yoon, Salvador Blanco
High‐resolution surface deformation and slip distribution observations for the 2023 Kahramanmaraş, Türkiye, earthquake sequence help constrain the rupture process High‐resolution surface deformation and slip distribution observations for the 2023 Kahramanmaraş, Türkiye, earthquake sequence help constrain the rupture process
Splay, or branch, faults are a common geometric feature of earthquake surface ruptures and may provide constraints on the rupture behavior of an earthquake. The 2023 Mw 7.8 Pazarcık and Mw 7.5 Elbistan, Türkiye, earthquakes are examples of ruptures with multiple small splays, and the Pazarcık earthquake nucleated on a splay fault, the Narlı fault, before rupturing bilaterally on the East...
Authors
Nadine G. Reitman, M. Morow Tan, Paula Madeline Burgi, Alexandra Elise Hatem, Christopher B. DuRoss, Richard W. Briggs
Three new calcium formate reference materials for δ13C measurements and a redetermination of the R(13C/12C) ratio for VPDB based on proton nuclear magnetic resonance measurements Three new calcium formate reference materials for δ13C measurements and a redetermination of the R(13C/12C) ratio for VPDB based on proton nuclear magnetic resonance measurements
Rationale
Authors
David W. Hoffman, Cornelia Rasmussen, Arndt Schimmelmann, Lauren T Reid, Haiping Qi, Tyler B. Coplen
Reaffirming the consistency of the original stock of NBS 19 limestone and its byproduct with finer grain size for δ13C and δ18O calibrations—Both distributed internationally Reaffirming the consistency of the original stock of NBS 19 limestone and its byproduct with finer grain size for δ13C and δ18O calibrations—Both distributed internationally
Rationale
Authors
Haiping Qi, Tyler B. Coplen, Lauren T Reid, Stanley J. Mroczkowski
Mars as one system: Insights from the 8th international conference on Mars polar science and exploration Mars as one system: Insights from the 8th international conference on Mars polar science and exploration
The 8th International Conference on Mars Polar Science and Exploration (ICMPSE) provided new insights into the complex interplay between Martian ice, climate, and atmospheric dynamics. The conference emphasized a holistic view of Mars as a system, where surface processes, subsurface ice, atmospheric dynamics, and historical climate shifts are interconnected. Research updates spanned...
Authors
Isaac B. Smith, Chimira Andres, Shannon Hibbard, Stefano Nerozzi, Roberto Aguilar, Peter Buhler, Ben Cornford, Leslie Tamppari, Timothy N. Titus
High and dry: The persistence of diverse coastal marsh communities depends on available upland area and connection to surrounding waters High and dry: The persistence of diverse coastal marsh communities depends on available upland area and connection to surrounding waters
Sea-level-rise and alterations to natural hydrology have contributed to coastal land loss. To combat coastal land loss and maintain the ecosystem services provided by marshes, marsh creation has been broadly implemented. Marsh creation projects can be performed in conjunction with the construction of elevated terrestrial ridges that seek to mimic historic delta-formed distributary ridges...
Authors
Erik Naiti-Johnson, Jonathan M. Willis, Gregg A. Snedden, Giovanna McClenachan
A simplified two-station approach for modeling metabolism in dam tailwaters subject to diel flow variation A simplified two-station approach for modeling metabolism in dam tailwaters subject to diel flow variation
Tailwaters are ubiquitous and highly managed ecosystems whose food webs often rely disproportionately on autochthonous energy. In situ continuous dissolved oxygen data are increasingly being used to estimate gross primary productivity and ecosystem respiration in rivers, but this approach is complicated in tailwaters, where upriver discontinuities (i.e., dams) violate commonly employed...
Authors
Ian Wesley Bishop, Bridget R. Deemer, Theodore Kennedy, Robert A. Payn, Robert O. Hall, Charles B. Yackulic
Mercury biomagnification across food webs with varying non-native fish presence: Implications for native fish conservation in the upper Colorado River Basin Mercury biomagnification across food webs with varying non-native fish presence: Implications for native fish conservation in the upper Colorado River Basin
Environmental contaminants and non-native species introductions negatively affect aquatic ecosystem conservation. Mercury (Hg) accumulates within food webs where it can biomagnify to toxic concentrations, which can be affected by altered trophic relationships from non-native species. This study examined Hg concentrations (n samples = 655) and stable carbon and nitrogen isotope (n = 746)
Authors
Charles F. Wahl, Natalie K. Day, Travis S. Schmidt, James J. Roberts, Jessica E. Brandt, Craig A. Stricker