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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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Temperatures of the Lacus Mortis region of the Moon Temperatures of the Lacus Mortis region of the Moon

Over 11 years of data acquired by the Diviner Lunar Radiometer Experiment instrument aboard Lunar Reconnaissance Orbiter have been compiled into a comprehensive data set of surface temperatures in the Lacus Mortis region which includes the landing ellipse of the Astrobotic Mission One lander mission. These data provide diurnal brightness temperatures at 128 pixels per degree (ppd)...
Authors
Jean-Pierre Williams, Benjamin T Greenhagen, Kristen A. Bennett, David Paige, Nandita Kumari, Caitlin Ahrens, Lior Rubanenko, Tyler Powell, Parvathy Prem, David T. Blewett, Patrick Russell, Paul O. Hayne, Mark Sullivan

Phytoplankton community interactions and cyanotoxin mixtures in three recurring surface blooms within one lake Phytoplankton community interactions and cyanotoxin mixtures in three recurring surface blooms within one lake

Cyanobacteria can produce numerous secondary metabolites (cyanotoxins) with various toxicities, yet data on cyanotoxins in many lakes are limited. Moreover, little research is available on complex relations among cyanobacteria that produce toxins. Therefore, we studied cyanobacteria and 19 cyanotoxins at three sites with recurring blooms in Kabetogama Lake (USA). Seven of 19 toxins were...
Authors
Victoria Christensen, Hayley T. Olds, Jack E. Norland, Eakalak Khan

Capturing the changing cryosphere with seismic horizontal-vertical spectral ratios Capturing the changing cryosphere with seismic horizontal-vertical spectral ratios

Changes in Earth’s cryosphere can have direct impacts on ecosystems, wildlife, and human communities that may extend to other reaches of the planet, such as through sea-level rise or altering the global carbon budget. Advances in passive seismic technology and processing methods have opened new opportunities to better understand how ice and permafrost soils are responding to changing...
Authors
Nathan T. Stevens, Stephanie R. James

New insights into organic matter accumulation from high-resolution geochemical analysis of a black shale: Middle and Upper Devonian Horn River Group, Canada New insights into organic matter accumulation from high-resolution geochemical analysis of a black shale: Middle and Upper Devonian Horn River Group, Canada

Organic matter (OM) accumulation in organic matter-rich mudstones, or black shales, is generally recognized to be controlled by combinations of bioproductivity, preservation, and dilution. However, specific triggers of OM deposition in these formations are commonly difficult to identify with geochemical proxies, in part because of feedbacks that cause geochemical proxies for these...
Authors
Haolin Zhou, Nicholas B. Harris, Tian Dong, Korhan Ayranci, Jilu Feng, Benoit Rivard, Paul C. Hackley, Javin J. Hatcherian

Mapped predictions of manganese and arsenic in an alluvial aquifer using boosted regression trees Mapped predictions of manganese and arsenic in an alluvial aquifer using boosted regression trees

Manganese (Mn) concentrations and the probability of arsenic (As) exceeding the drinking-water standard of 10 μg/L were predicted in the Mississippi River Valley alluvial aquifer (MRVA) using boosted regression trees (BRT). BRT, a type of ensemble-tree machine-learning model, were created using predictor variables that affect Mn and As distribution in groundwater. These variables...
Authors
Katherine J. Knierim, James A. Kingsbury, Kenneth Belitz, Paul E. Stackelberg, Burke J. Minsley, James R. Rigby

A statistical framework to track temporal dependence of chlorophyll–nutrient relationships with implications for lake eutrophication management A statistical framework to track temporal dependence of chlorophyll–nutrient relationships with implications for lake eutrophication management

A reliable chlorophyll–nutrient relationship (CNR) is essential for lake eutrophication management. Although the spatial variability of CNRs has been extensively explored, temporal variations of CNRs at the individual lake scale has rarely been discussed. The paucity of information about temporal dependence in CNRs may in part be due to the lack of a suitable statistical framework that...
Authors
Qianlinglin Qiu, Zhongyao Liang, Yaoyang Xu, Shin-Ichiro S. Matsuzaki, Kazuhiro Komatsu, Tyler Wagner

Does where they start affect where they finish? A multimethod investigation of the role of stocking location on survival and dispersal of hatchery-reared Lake Sturgeon in Missouri River tributaries Does where they start affect where they finish? A multimethod investigation of the role of stocking location on survival and dispersal of hatchery-reared Lake Sturgeon in Missouri River tributaries

Despite ongoing Lake Sturgeon recovery efforts, little is known about the role of stocking location on survival and dispersal to nursery habitats. We stocked age-0 Lake Sturgeon at four sites in two adjacent Missouri River tributaries and used telemetry to examine whether survival and dispersal differed among stocking sites and rivers. Survival estimates from Barker Cormack-Jolly-Seber...
Authors
M.J. Moore, Craig P. Paukert, T.W. Bonnot, B. Brooke, T. Moore

Relationship of trout growth to frequent electrofishing and diet collection in a headwater stream Relationship of trout growth to frequent electrofishing and diet collection in a headwater stream

Research on fishes sometimes requires that individual fish be captured and subjected to invasive procedures multiple times over a relatively short time span. Electrofishing is one of the most common techniques used to capture fish, and it is known to cause injury to fish under certain circumstances. We evaluated the relationship of growth rates in Columbia River Redband Trout...
Authors
Niall G. Clancy, James L. Dunnigan, Phaedra E. Budy

Salinity contributions from geothermal waters to the Rio Grande and shallow aquifer system in the transboundary Mesilla (United States)/Conejos-Médanos (Mexico) Basin Salinity contributions from geothermal waters to the Rio Grande and shallow aquifer system in the transboundary Mesilla (United States)/Conejos-Médanos (Mexico) Basin

Freshwater scarcity has raised concerns about the long-term availability of the water supplies within the transboundary Mesilla (United States)/Conejos-Médanos (Mexico) Basin in Texas, New Mexico, and Chihuahua. Analysis of legacy temperature data and groundwater flux estimates indicates that the region’s known geothermal systems may contribute more than 45,000 tons of dissolved solids...
Authors
Jeff D. Pepin, Andrew J. Robertson, Shari A. Kelley

Effects of diet and provisioning behavior on chick growth in Adélie Penguins (Pygoscelis adeliae) Effects of diet and provisioning behavior on chick growth in Adélie Penguins (Pygoscelis adeliae)

When provisioning chicks, parents trade-off their time, energy, and other resources to maximize reproductive success. As parents adjust investment to maximize their fitness, impacts on offspring growth can occur. We investigated provisioning and chick growth of Adélie Penguins (Pygoscelis adeliae) at one of the largest colonies (∼175,000 pairs), during one year of normal chick growth and...
Authors
Scott Jennings, Katie M. Dugger, Grant Ballard, David G. Ainley

Improving groundwater model calibration with repeat microgravity measurements Improving groundwater model calibration with repeat microgravity measurements

Groundwater-flow models depend on hydraulic head and flux observations for evaluation and calibration. A different type of observation—change in storage measured using repeat microgravity—can also be used for parameter estimation by simulating the expected change in gravity from a groundwater model and including the observation misfit in the objective function. The method is demonstrated...
Authors
Jeffrey R. Kennedy, Libby M. Wildermuth, Jacob E. Knight, Joshua D. Larson

Foraging movements and colony attendance of Least Terns (Sternula antillarum) on the central Platte River, Nebraska, USA Foraging movements and colony attendance of Least Terns (Sternula antillarum) on the central Platte River, Nebraska, USA

Least Terns (Sternula antillarum) are known to forage away from nesting colonies, yet little information is available about movement rates and distances. We used VHF transmitters and a network of datalogging receivers to monitor movements of 23 Least Terns on the central Platte River, Nebraska, USA. We typically detected incubating and brood-rearing birds within 8 km of colonies during...
Authors
Mark H. Sherfy, Megan M. Ring, Jennifer H. Stucker, Michael J. Anteau, Terry L. Shaffer, Marsha A. Sovada
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