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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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Long-term mercury loading and trapping dynamics in a Western North America reservoir Long-term mercury loading and trapping dynamics in a Western North America reservoir
Study Region The Carson River including Lahontan Reservoir in Northwestern Nevada, USAStudy Focus The discovery, mining, and processing of silver and gold from the Comstock Lode in northwestern Nevada heavily contaminated the Carson River system with mercury (Hg). The river now contains some of the highest recorded water column and bed sediment Hg concentrations reported in peer-reviewed...
Authors
Eric D. Morway, Robert M. Hirsch, Angela Paul, Mark C. Marvin-DiPasquale, Carl E Thodal
Ring-necked Pheasant brood habitat selection and movements in an intensive agricultural landscape Ring-necked Pheasant brood habitat selection and movements in an intensive agricultural landscape
Management of row crops can greatly influence wildlife populations in an agriculturally intensive landscape. Many upland gamebird populations, including Phasianus colchicus L. (Ringnecked Pheasant; hereafter pheasant) are experiencing contemporary population declines in such landscapes throughout the Midwest United States. Reduced availability of quality brood habitat may be a factor in...
Authors
Alixandra Godar, Adela Piernicky, David A. Haukos, Jeff Prendergast
LakeLevel tracker: A Google Earth engine-based web application for characterizing lake water levels LakeLevel tracker: A Google Earth engine-based web application for characterizing lake water levels
No abstract available.
Authors
Abhishek Kumar, Allison H. Roy, Konstantinos Andreadis, Xinchen He, Caitlyn Butler
Gopherus Agassizii (Mojave Desert Tortoise). nest depredation Gopherus Agassizii (Mojave Desert Tortoise). nest depredation
Nest site selection is an important determinant of clutch success and hatchling sex ratios in Gopherus agassizii, Mojave Desert tortoises (Spotila et al. 1994. Herpetol. Monogr. 8:103-116). G. agassizii lay eggs in or near the entrance of their burrows (Ennen et al. 2012. Copeia 2012:222-228) and females of both G. agassizii and G. morafkai, may reduce egg predation risk by remaining at...
Authors
Megan Peukert, Gerardo Avila, William J. Hoese, Christopher R. Tracy, Philip L. Boyd, Kristy L. Cummings, Shellie R. Puffer, Jeffrey E. Lovich
Leveraging angler effort to inform fisheries management: Using harvest and harvest rate to estimate abundance of White Sturgeon Leveraging angler effort to inform fisheries management: Using harvest and harvest rate to estimate abundance of White Sturgeon
Traditional methods for estimating abundance of fish populations are not feasible in some systems due to complex population structure and constraints on sampling effort. Lincoln’s estimator provides a technique that uses harvest and harvest rate to estimate abundance. Using angler catch data allows assumptions of the estimator to be addressed without relying on methods that could be...
Authors
Marta Ulaski, Joshua McCormick, Michael C. Quist, Zachary Jackson
Evidence of a load-lightening helper effect in Florida Scrub-Jays: Implications for translocation Evidence of a load-lightening helper effect in Florida Scrub-Jays: Implications for translocation
The Florida Scrub-Jay (Aphelocoma coerulescens) is an imperiled cooperatively breeding species endemic to Florida scrub habitats. Translocation of non-reproductive helpers has been proposed as a conservation tool to increase population size and connectivity. However, the potential consequences of helper removal on the source population remain unclear because the benefits provided by...
Authors
Alexis Cardas, Erin Hewett Ragheb, Karl E. Miller, Abby Powell
The lunar cratering chronology The lunar cratering chronology
This chapter provides an introduction to crater-size frequency distribution (CSFD) measurements and presents a review of the work performed on dating lunar geological units using CSFDs since the last New Views of the Moon volume (2006), including various volcanic and tectonic features, as well as individual impact craters. At the end of the chapter, implications for the new CSFD age...
Authors
Harald Hiesinger, Carolyn H. Van der Bogert, G. Michael, N. Schmedemann, W. Iqbal, Stuart J. Robbins, B. Ivanov, Jean-Pierre Williams, M. Zanetti, J. Plescia, Lillian R. Ostrach, James W. Head III
Lunar mare basaltic volcanism: Volcanic features and emplacement processes Lunar mare basaltic volcanism: Volcanic features and emplacement processes
Volcanism is a fundamental process in the geological evolution of the Moon, providing clues to the composition and structure of the mantle, the location and duration of interior melting, the nature of convection and lunar thermal evolution. Progress in understanding volcanism has been remarkable in the short 60-year span of the Space Age. Before Sputnik 1 in 1957, the lunar farside was...
Authors
James W. Head III, Lionel Wilson, Harald Hiesinger, Carolyn H. Van der Bogert, Yuan Yuan Chen, James L. Dickson, Lisa Gaddis, Junichi Haruyama, Lauren Jozwiak, Erica Jawin, Chunlai Li, Jianzhong Liu, Tomokatsu Morota, Debra H. Needham, Lillian R. Ostrach, Carle M. Pieters, Tabb C. Prissel, Yuqi Qian, Lei Qiao, Malcolm R. Rutherford, David R. Scott, Jennifer L. Whitten, Long Xiao, Feng Zhang, Ouyang Ziyuan
Geographic distribution: Incilius alvarius (Sonoran desert toad) Geographic distribution: Incilius alvarius (Sonoran desert toad)
No abstract available.
Authors
Erika M. Nowak, Karina Cocks, Charles A. Drost, Janie Agyagos, Eve Berlinksy, Jennifer Steffen, Rafal Banas, Meredith Talbert, Sara Eno
Examining current bias and future projection consistency of globally downscaled climate projections commonly used in climate impact studies Examining current bias and future projection consistency of globally downscaled climate projections commonly used in climate impact studies
The associated uncertainties of future climate projections are one of the biggest obstacles to overcome in studies exploring the potential regional impacts of future climate shifts. In remote and climatically complex regions, the limited number of available downscaled projections may not provide an accurate representation of the underlying uncertainty in future climate or the possible...
Authors
Lucas Berio Fortini, Lauren R. Kaiser, Abby G. Frazier, Thomas W Giambelluca
Discovery of an active forearc fault in an urban region: Holocene rupture on the XEOLXELEK-Elk Lake fault, Victoria, British Columbia, Canada Discovery of an active forearc fault in an urban region: Holocene rupture on the XEOLXELEK-Elk Lake fault, Victoria, British Columbia, Canada
Subduction forearcs are subject to seismic hazard from upper plate faults that are often invisible to instrumental monitoring networks. Identifying active faults in forearcs therefore requires integration of geomorphic, geologic, and paleoseismic data. We demonstrate the utility of a combined approach in a densely populated region of Vancouver Island, Canada, by combining remote sensing
Authors
Nicolas Harrichhausen, Theron Finley, Kristin D. Morell, Christine Regalla, Scott E.K. Bennett, Lucinda J. Leonard, Edwin Nissen, Eleanor McLeod, Emerson M. Lynch, Guy Salomon, Israporn Sethanant
Simulation modeling to assess line transect distance sampling under a range of translocation scenarios Simulation modeling to assess line transect distance sampling under a range of translocation scenarios
The accuracy of posttranslocation population monitoring methods is critical to assessing long-term success in translocation programs. Translocation can produce unique challenges to monitoring efforts; therefore, it is important to understand the flexibility and robustness of commonly used monitoring methods. In Florida, USA, thousands of gopher tortoises Gopherus polyphemus have been...
Authors
Max D. Jones, Lora L. Smith, Katherine Gentry Richardson, J. Nicole DeSha, Traci Castellón, Dan Hipes, Alex Kalfin, Neal T. Halstead, Elizabeth Ann Hunter