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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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Sexual dimorphism in endangered Jemez Mountains Salamanders (Plethodon neomexicanus) Sexual dimorphism in endangered Jemez Mountains Salamanders (Plethodon neomexicanus)
Sex ratio is a key demographic characteristic indicative of the condition of populations. Despite over 70 yr of study, researchers have not fully evaluated morphological characteristics that differentiate sex in Jemez Mountains Salamanders (Plethodon neomexicanus; federally endangered). Populations of this endemic salamander, which are distributed in north-central New Mexico, have...
Authors
Nancy E. Karraker, Rachel A. Loehman, Samantha Cordova
Modeling non-structural strategies to reduce pedestrian evacuation times for mitigating local tsunami threats in Guam Modeling non-structural strategies to reduce pedestrian evacuation times for mitigating local tsunami threats in Guam
Reducing the potential for loss of life from local tsunamis is challenging for emergency managers given the need for self-protective behavior of at-risk individuals within brief windows of time to evacuate. There has been considerable attention paid to discussing the use of tsunami vertical-evacuation structures for areas where there may be insufficient time to evacuate. This strategy...
Authors
Nathan J. Wood, Jeff Peters, Kwok Fai Cheung, Yoshiki Yamazaki, Denille Calvo, Charles Guard
Mammalian resistance to megafire in western U.S. woodland savannas Mammalian resistance to megafire in western U.S. woodland savannas
Increasingly frequent megafires are dramatically altering landscapes and critical habitats around the world. Across the western United States, megafires have become an almost annual occurrence, but the implication of these fires for the conservation of native wildlife remains relatively unknown. Woodland savannas are among the world's most biodiverse ecosystems and provide important food...
Authors
Kendall L. Calhoun, Benjamin R. Goldstein, Kaitlyn M. Gaynor, Michael C Mcinturff, Leonel Solorio, Justin S. Brashares
Debris-flow process controls on steepland morphology in the San Gabriel Mountains, California Debris-flow process controls on steepland morphology in the San Gabriel Mountains, California
Steep landscapes evolve largely by debris flows, in addition to fluvial and hillslope processes. Abundant field observations document that debris flows incise valley bottoms and transport substantial sediment volumes, yet their contributions to steepland morphology remain uncertain. This has, in turn, limited the development of debris-flow incision rate formulations that produce...
Authors
William Struble, Luke A. McGuire, Scott W. McCoy, Katherine R. Barnhart, Odin Marc
Prioritizing the risk and management of introduced species in a landscape with high indigenous biodiversity Prioritizing the risk and management of introduced species in a landscape with high indigenous biodiversity
Risk analysis protocols for prioritizing the management of non-native species are numerous, yet few incorporate risk and management in the same analysis or accommodate a broad diversity of taxa outside of a specific geographic area. We adapted a protocol that accounts for these factors to address non-native animal species in the Southern California/Northern Baja California Coast...
Authors
Jonathan Q. Richmond, Jennifer Kingston, Brittany Ewing, Wendy M Bear, Stacie A. Hathaway, Cedric Lee, Camm C. Swift, Kristine L. Preston, Allison J. Schultz, Barbara E. Kus, Kerwin Russell, Philip Unitt, Bradford D. Hollingsworth, Robert E. Espinoza, Michael Wall, Scott Tremor, Kai Palenscar, Robert N. Fisher
Persistence of native riverine fishes downstream from two hydropower dams with contrasting operations Persistence of native riverine fishes downstream from two hydropower dams with contrasting operations
Identifying hydropower dam operations that lessen detrimental effects on downstream fauna could inform conservation strategies for native fishes. We compared occurrence of native fishes in 20 shoal habitats downstream from two differently operated hydropower dams in the Coosa River system, Georgia, USA. Species richness averaged 7 and 11, respectively, in surveys downstream from (1) a...
Authors
Mary Freeman, Brett Albanese, Phillip M. Bumpers, Megan M. Hagler, Andrew J. Nagy, Byron J. Freeman, Seth J. Wenger
Lake sturgeon population trends in the St. Clair–Detroit River System, 2001–2019 Lake sturgeon population trends in the St. Clair–Detroit River System, 2001–2019
Lake Sturgeon Acipenser fulvescens are listed as threatened or endangered in 15 states or provinces within their native range. Accordingly, investments in habitat and population restoration for this species have increased throughout the Great Lakes. To aide evaluation of restoration efficacy, robust population parameters are needed to inform management decisions. The St. Clair – Detroit...
Authors
Justin A. Chiotti, James C. Boase, Andrew S Briggs, Chris Davis, Richard Drouin, Darryl W. Hondorp, Lloyd Mohr, Edward F. Roseman, Michael V. Thomas, Todd C. Wills
Extrusion tectonism of Indochina reassessed: constraints from 40Ar/39Ar geochronology from the Day Nui Con Voi metamorphic massif, Vietnam Extrusion tectonism of Indochina reassessed: constraints from 40Ar/39Ar geochronology from the Day Nui Con Voi metamorphic massif, Vietnam
The extrusion tectonic model for the southeastern margin of the Himalayan orogeny links the crustal shear activity along the Red River Shear Zone (RRSZ) to the opening of the South China Sea (SCS). The Day Nui Con Voi (DNCV) metamorphic massif in northern Vietnam strikes NW-SE, is bounded by the RRSZ to the south and continues along the strike where it meets the SCS. The DNCV is thus a...
Authors
Thi-Hue Dinh, Meng-Wan Yeh, Tung-Yi Lee, Michael J. Kunk, Robert P. Wintsch, Ryan J. McAleer
Impacts of a Cascadia subduction zone earthquake on water levels and wetlands of the lower Columbia River and Estuary Impacts of a Cascadia subduction zone earthquake on water levels and wetlands of the lower Columbia River and Estuary
Subsidence after a subduction zone earthquake can cause major changes in estuarine bathymetry. Here, we quantify the impacts of earthquake-induced subsidence on hydrodynamics and habitat distributions in a major system, the lower Columbia River Estuary, using a hydrodynamic and habitat model. Model results indicate that coseismic subsidence increases tidal range, with the smallest...
Authors
M.W. Brand, H.L. Diefenderfer, Jim E. O'Connor, A.B. Borde, D.A. Jay, A. Al-Bahadily, M. McKeon, S.A. Talke
River geomorphology affects biogeochemical responses to hydrologic events in a large river ecosystem River geomorphology affects biogeochemical responses to hydrologic events in a large river ecosystem
Shifts in the frequency and intensity of high discharge events due to climate change may have important consequences for the hydrology and biogeochemistry of rivers. However, our understanding of event-scale biogeochemical dynamics in large rivers lags that of small streams. To fill this gap, we used high-frequency sensor data collected during four consecutive summers from a main channel...
Authors
Taryn Waite, Kathi Jo Jankowski, Denise Bruesewitz, Molly Van Appledorn, Megan Johnston, Jeffrey N. Houser, Douglas Baumann, Barbara Bennie
A recruitment niche framework for improving seed-based restoration A recruitment niche framework for improving seed-based restoration
As larger tracts of land experience degradation, seed-based restoration (SBR) will be a primary tool to reestablish vegetation and ecosystem function. SBR has advanced in terms of technical and technological approaches, yet plant recruitment remains a major barrier in some systems, notably drylands. There is an unmet opportunity to test science-based approaches to seed mix design and...
Authors
Julie E. Larson, A. C. Agneray, Chad S. Boyd, John B. Bradford, O. A. Kildisheva, Katharine N. Suding, Stella M. Copeland
An algorithm for correction of atmospheric scattering dilution effects in volcanic gas emission measurements using skylight differential optical absorption spectroscopy An algorithm for correction of atmospheric scattering dilution effects in volcanic gas emission measurements using skylight differential optical absorption spectroscopy
Differential Optical Absorption Spectroscopy (DOAS) is commonly used to measure gas emissions from volcanoes. DOAS instruments measure the absorption of solar ultraviolet (UV) radiation scattered in the atmosphere by sulfur dioxide (SO2) and other trace gases contained in volcanic plumes. The standard spectral retrieval methods assume that all measured light comes from behind the plume...
Authors
Bo Galle, Santiago Arellano, Mattias Johansson, Christoph Kern, Melissa Pfeffer