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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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Early Neoproterozoic gold deposits of the Alto Guaporé province, southwestern Amazon craton, western Brazil Early Neoproterozoic gold deposits of the Alto Guaporé province, southwestern Amazon craton, western Brazil
The Alto Guaporé gold province, southwestern Amazon craton, contains gold deposits that have been mined since the beginning of the 18th century and these deposits, together, have modern-day, pre-mining gold resources of at least 1.8 Moz. The ore is associated with quartz vein systems along the southeastern part of the Aguapei belt, a ~35-km-wide and ~500-km-long, NNW-trending shear zone...
Authors
Rodrigo Prudente de Melo, Marcos Aurelio Farias de Oliveira, Richard J. Goldfarb, Craig A. Johnson, Erin E. Marsh, Roberto Perez Xavier, Leandro Rocha de Oliveira, Leah E. Morgan
Adaptive monitoring in support of adaptive management in rangelands Adaptive monitoring in support of adaptive management in rangelands
Monitoring supports iterative learning about the effectiveness of management actions, information that can help managers plan future actions, facilitate decision-making, and improve outcomes. Adaptive monitoring is the evolution of a monitoring program in response to new management questions; new or changing environmental or socioeconomic conditions, improved monitoring methods, models...
Authors
Sarah E. McCord, David S. Pilliod
Evidence of a dietary shift by the Florida manatee (Trichechus manatus latirostris) in the Indian River Lagoon inferred from stomach content analyses Evidence of a dietary shift by the Florida manatee (Trichechus manatus latirostris) in the Indian River Lagoon inferred from stomach content analyses
Investigating the long-term fluctuations of the feeding ecology of megaherbivores such as sirenians is important, as any changes could be indicative of shifts in resource availability. The Indian River Lagoon (IRL), eastern Florida, USA, is a critical habitat for the Florida manatee (Trichechus manatus latirostris). However, the IRL has experienced a substantial decline in seagrass due...
Authors
Aarin Conrad Allen, Cathy Beck, Danielle C. Sattelberger, Jeremy J. Kiszka
Stage-specific environmental correlates of reproductive success in Boreal Toads (Anaxyrus boreas boreas) Stage-specific environmental correlates of reproductive success in Boreal Toads (Anaxyrus boreas boreas)
Compensatory recruitment can facilitate the persistence of populations experiencing high adult mortality. Because early life-stages of many taxa, including amphibians, are difficult to mark and recapture, sources of variation in survival at these stages often are unknown, which creates barriers to improving in situ recruitment rates. We leveraged count data and open N-mixture models to...
Authors
Gabriel M. Barrile, Annika W. Walters, Anna D. Chalfoun
How low should we alert? Quantifying intensity threshold alerting strategies for earthquake early warning in the United States How low should we alert? Quantifying intensity threshold alerting strategies for earthquake early warning in the United States
We use a suite of historical earthquakes to quantitatively determine earthquake early warning (EEW) alert threshold strategies for a range of shaking intensity targets for EEW in the U.S. West Coast. The current method for calculating alert regions for the ShakeAlert EEW System does not take into account variabilities and uncertainties in shaking distribution. As a result, if the...
Authors
Jessie Kate Saunders, Sarah E. Minson, Annemarie S. Baltay
Identifying factors linked with persistence of reintroduced populations: Lessons learned from 25 years of amphibian translocations Identifying factors linked with persistence of reintroduced populations: Lessons learned from 25 years of amphibian translocations
Conservation translocations are increasingly used to help recover imperiled species. However, success of establishing populations remains low, especially for amphibians. Identifying factors associated with translocation success can help increase efficiency and efficacy of recovery efforts. Since the 1990s, several captive and semi-captive facilities have produced Chiricahua Leopard Frogs...
Authors
Blake R. Hossack, Paige E. Howell, Audrey K Owens, C Cobos, Caren S. Goldberg, David L. Hall, Shaula Hedwall, Susi MacVean, Magnus McCaffery, A. Hunter McCall, C Mosley, Emily Bea Oja, James C. Rorabaugh, Brent H. Sigafus, Michael J Sredl
Using genetic data to advance stream fish reintroduction science: A case study in brook trout Using genetic data to advance stream fish reintroduction science: A case study in brook trout
Widespread extirpation of native fish populations has led to a rise in species reintroduction efforts worldwide. Most efforts have relied on demographic data alone to guide project design and evaluate success. However, the genetic characteristics of many imperiled fish populations including low diversity, local adaptation, and hatchery introgression emphasize the importance of genetic...
Authors
Shannon L. White, Thomas C Johnson, Jacob M Rash, Barbara A. Lubinski, David C. Kazyak
Temperature optimum for marsh resilience and carbon accumulation revealed in a whole ecosystem warming experiment Temperature optimum for marsh resilience and carbon accumulation revealed in a whole ecosystem warming experiment
Coastal marshes are globally important, carbon dense ecosystems simultaneously maintained and threatened by sea-level rise. Warming temperatures may increase wetland plant productivity and organic matter accumulation, but temperature-modulated feedbacks between productivity and decomposition make it difficult to assess how wetlands and their thick, organic rich soils will respond to...
Authors
Alexander J. Smith, Genevieve L. Noyce, J. Patrick Megonigal, Glenn R. Guntenspergen, Matthew L. Kirwan
A novel application of hierarchical modelling to decouple sampling artifacts from socio-ecological effects on poaching intensity A novel application of hierarchical modelling to decouple sampling artifacts from socio-ecological effects on poaching intensity
Poaching is a global driver of wildlife population decline, including inside protected areas (PAs). Reducing poaching requires an understanding of its cryptic drivers and accurately quantifying poaching scales and intensity. There is little quantification of how poaching is affected by law enforcement intensity (e.g., ranger stations) versus economic factors (e.g., unemployment), while
Authors
Mahmood Soofi, Ali T. Qashqaei, Jan-Niklas Trei, Shirko Shokri, Javad Selyari, Benjamin Ghasemi, Poorya Sepahvand, Lukas Egli, Bagher Nezami, Navid Zamani, Gholam Hosein Yusefi, Bahram H. Kiabi, Niko Balkenhol, J. Andrew Royle, Chris R. Pavey, Steve M. Redpath, Matthias Waltert
Multi-task deep learning of daily streamflow and water temperature Multi-task deep learning of daily streamflow and water temperature
Deep learning (DL) models can accurately predict many hydrologic variables including streamflow and water temperature; however, these models have typically predicted hydrologic variables independently. This study explored the benefits of modeling two interdependent variables, daily average streamflow and daily average stream water temperature, together using multi-task DL. A multi-task...
Authors
Jeffrey Michael Sadler, Alison P. Appling, Jordan Read, Samantha K. Oliver, Xiaowei Jia, Jacob Aaron Zwart, Vipin Kumar
Assessing mineral supply concentration from different perspectives through a case study of zinc Assessing mineral supply concentration from different perspectives through a case study of zinc
Increasing demand for nonfuel mineral commodities has increased concerns regarding the reliability of their supplies. “Criticality” assessments over the past decade have attempted to capture this concern through a set of indicators, the most common of which quantifies the risk associated with market concentration by applying the Herfindahl-Hirschman Index (HHI) to the world production of...
Authors
Christine L. Thomas, Nedal T. Nassar, John H. DeYoung
Contrasting Common Era climate and hydrology sensitivities from paired lake sediment dinosterol hydrogen isotope records in the South Pacific Convergence Zone Contrasting Common Era climate and hydrology sensitivities from paired lake sediment dinosterol hydrogen isotope records in the South Pacific Convergence Zone
Hydroclimate on ‘Uvea (Wallis et Futuna) is controlled by rainfall associated with the South Pacific Convergence Zone (SPCZ), the southern hemisphere's largest precipitation feature. To extend the short observational precipitation record, the hydrogen isotopic composition of the algal lipid biomarker dinosterol (δ2Hdinosterol) was measured in sediment cores from two volcanic crater lakes...
Authors
Ashley E. Maloney, Julie N. Richey, Daniel B. Nelson, Samantha N Hing, David A. Sear, Jonathan D. Hassall, Peter G. Langdon, Ursula Sichrowsky, Robert Schabetsberger, Atoloto Malau, Jean-Yves Meyer, Ian W. Croudace, Julian P. Sachs