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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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Insights on arc magmatic systems drawn from natural melt inclusions and crystallization experiments at PH2O=800 MPa under oxidizing conditions Insights on arc magmatic systems drawn from natural melt inclusions and crystallization experiments at PH2O=800 MPa under oxidizing conditions

Whole rock compositions at Buldir Volcano, western Aleutian arc, record a strong, continuous trend of iron depletion with decreasing MgO, classically interpreted as a calc-alkaline liquid line of descent. In contrast, olivine-hosted melt inclusions have higher total iron (FeO*) than whole rocks and show little change in FeO* with decreasing MgO. To investigate this discrepancy and...
Authors
Janine L. Andrys, Elizabeth Cottrell, Katherine A. Kelley, Laura E. Waters, Michelle L. Coombs

Trends and environmental impacts of virtual water trade Trends and environmental impacts of virtual water trade

Virtual water describes water embedded in the production of goods and offers meaningful insights about the complex interplay between water, trade and sustainability. In this Review, we examine the trends, major players, traded products and key drivers of virtual water trade (VWT). Roughly 20% of water used in global food production is traded virtually rather than domestically consumed...
Authors
Mesfin M. Mekonnen, Mahlet M. Kebede, Betelhem W. Demeke, Joel A. Carr, Ashok Chapagain, Carole Dalin, Peter Debaere, Paolo D’Odorico, Landon Marston, Chittaranjan Ray, Lorenzo Rosa, La Zhuo

River suspended-sand flux computation with uncertainty estimation using water samples and high-resolution ADCP measurements River suspended-sand flux computation with uncertainty estimation using water samples and high-resolution ADCP measurements

Measuring suspended-sand fluxes in rivers remains a scientific challenge due to their high spatial and temporal variability. To capture the vertical and lateral gradients of concentration in the cross-section, measurements with point samples are performed. However, the uncertainty related to these measurements is rarely evaluated, as few studies of the major sources of error exist...
Authors
Jessica Marggraf, Guillaume Dramais, Jerome Le Coz, Blaise Calmel, Benoit Camenen, David J. Topping, William Santini, Gilles Pierrefeu, François Lauters

Formation of vertical columnar seismic structures and seafloor depressions by groundwater discharge in the drowned Miami Terrace platform and overlying deep-water carbonates, southeastern Florida Formation of vertical columnar seismic structures and seafloor depressions by groundwater discharge in the drowned Miami Terrace platform and overlying deep-water carbonates, southeastern Florida

The presence of vertical cross-formational fluid migration passageways within sedimentary basins can profoundly impact aquifer and reservoir fluid-flow and their identification is fundamental to informing management of subsurface fluid resources (groundwater, oil, gas). In an onshore and offshore southeastern part of Florida, 2D/3D seismic-reflection and bathymetry data document ∼153...
Authors
Kevin J. Cunningham, Richard L. Westcott, Sean Norgard, Edward Robinson, Harry J. Dowsett, Marci M. Robinson

Reducing uncertainty with iterative model updating parses effects of competition and environment on salamander occupancy Reducing uncertainty with iterative model updating parses effects of competition and environment on salamander occupancy

Making timely management decisions is often hindered by uncertainty. Monitoring reduces two key types of uncertainty. First, it serves to reduce structural uncertainty of how the system works and provides support for expectations of how a system works. Second, it serves to reduce parametric uncertainty of the drivers of system dynamics. By combining monitoring data and quantitative...
Authors
Jo Avital Werba, Graziella Vittoria DiRenzo, Adrianne Brand, Evan H. Campbell Grant

Ceanothus: Taxonomic patterns in life history responses to fire Ceanothus: Taxonomic patterns in life history responses to fire

Premise: Ceanothus (Rhamnaceae) is a large genus of shrubs that dominate California chaparral and are resilient to fires. Persistence is ensured by resprouting and/or seedling recruitment from dormant seed banks. Some species do both and others, the obligate seeders, are entirely dependent on seedling recruitment. The distribution of these two modes within the genus is poorly documented...
Authors
Jon Keeley, V. Thomas Parker, Paul H. Zedler, R. Brandon Pratt

Advancing water security in Africa with new high-resolution discharge data Advancing water security in Africa with new high-resolution discharge data

VegDischarge v1 is a comprehensive river discharge across Africa (2000–2021), produced by coupling the agro-hydrologic VegET model and the mizuRoute routing framework. Using remote sensing data and hydrological modeling, the 1-km runoff field simulated by VegET, and routed with mizuRoute, covers over 64,000 river segments in Africa. The VegET model simulates runoff based on vegetation...
Authors
Komlavi Akpoti, Naga Manohar Velpuri, Naoki Mizukami, Stefanie Kagone, Mansoor Leh, Kirubel Mekonnen, Afua Owusu, Primrose Tinonetsana, Michael Phiri, Lahiru Madushanka, Tharindu Perera, Paranamana T. Prabhath, Gabriel Edwin Lee Parrish, Gabriel B. Senay, Abdulkarim Seid

An evaluation of cyanobacterial occurrence and bloom development in Adirondack lakes An evaluation of cyanobacterial occurrence and bloom development in Adirondack lakes

Cyanobacterial harmful algal blooms (cyanoHABs) have occurred in many low nutrient (oligotrophic) lakes in the northeastern United States. The Adirondack Park in New York is a large, mountainous region with many low nutrient lakes. There is a gap in understanding regarding whether cyanoHAB reporting data are truly reflective of the susceptibility of lakes to develop bloom conditions. We...
Authors
Rebecca M. Gorney, Elizabeth A. Nystrom, Michael D.W. Stouder, Ann E. St. Amand, Cory Suave, Denise Clark, Erin A. Stelzer, Carrie E. Givens, Jennifer L. Graham

Long-term trends in abundance and potential drivers for eight species of coastal birds in the U.S. South Atlantic Long-term trends in abundance and potential drivers for eight species of coastal birds in the U.S. South Atlantic

The U.S. South Atlantic coastal region is used by many marine birds for foraging, reproduction, and migration. We developed standardized indices of relative abundance from long–term (1980–2016), semi-structured monitoring data (eBird) for eight species: Brown Pelican (Pelecanus occidentalis), Double-Crested Cormorant (Nannopterum auritum), White Ibis (Eudocimus albus), Wood Stork...
Authors
J.K. Craig, K.I. Siegfried, R.T. Cheshire, M. Karnauskas, Patrick G.R. Jodice

Individual return patterns of spawning flannelmouth sucker (Catostomus latipinnis) to a desert river tributary Individual return patterns of spawning flannelmouth sucker (Catostomus latipinnis) to a desert river tributary

Tributaries provide temporal and spatial habitat heterogeneity in river networks that can be critical for parts of the life history of a species. Tributary fidelity can benefit individual fish undergoing spawning migrations by reducing time and energy spent exploring new areas and leveraging previous experience, but anthropogenic activities that fragment or degrade these systems can...
Authors
Sophia Marie Bonjour, Keith B. Gido, Charles N. Cathcart, Mark C. McKinstry

The LTAR cropland Common Experiment at Lower Chesapeake Bay The LTAR cropland Common Experiment at Lower Chesapeake Bay

The Lower Chesapeake Bay (LCB) Long-Term Agroecosystem Research (LTAR) Common Experiment (CE) located in Beltsville, MD, focuses on research of concern to producers of the major regional crops, which are corn (Zea mays L.), soybean [Glycine max (L.) Merr.], wheat (Triticum aestivum L.), and various forage species. Livestock production in the region includes broiler and laying chickens...
Authors
Gwen Bagley, Victoria E.P. Ackroyd, Michelle A. Cavagielli, K. E. White, Harry H. Schomberg, E.P. Law, K. Bejleri, W. Dean Hively, M.H.H. Fischel, Jude E. Maul, Cathleen J. Hapeman, Gregory W. McCarty, Wayne Dulaney, Dennis J. Timlin, Steven B. Mirsky
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