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At least 577 records · Page 32Linked to original sources
USGS1981

Food of the Pacific white-sided dolphin, Lagenorhynchus obliquidens, Dall's porpoise, Phocoenoides dalli, and northern fur seal, Callorhinus ursinus, off California and Washington

Our knowledge of the feeding habits of the Pacific white-sided dolphin, Lagenorhynchus obliquidens , and the Dall's porpoise, Phocoenoides dalli , is based on examination of the stomach contents of stranded animals, animals accidentally taken in commercial fishing gear, those taken in the western Pacific commercial fishery, and animals that died during capture attempts. Of these only a few were normally feeding animals taken at sea, whose stomach contents were thoroughly examined. Fished and squids previously identified from stomachs of dolphins and porpoises by various investigators are listed in Table 1. This paper documents the stomach contents of 44 Pacific white-sided dolphin and 9 Dall's porpoise collected at sea off California and Washington. All animals were collected by the authors during pelagic fur seal studies with the exception of three dolphins which were collected by a staff biologist during whale research voyages off California. Comparisons of stomach contents are made between the Pacific white-sided dolphins, Dall's porpoise, and northern fur seal, Callorhinus ursinus , collected near the same locations and usually on the same day. Mention of the dolphin, porpoise , and seal in this paper refers to the above-named species unless noted otherwise.

California, Washington↗
USGS2018

UZIG research: Measurement and characterization of unsaturated zone processes under wide-ranging climates and changing conditions

Unsaturated zone properties and processes are central to understanding the interacting effects of land-use change, contamination, and hydroclimate on our ability to grow food, sustain clean water supplies, and minimize loss of life and property. Advances in unsaturated zone science are being achieved through collaborations across traditional boundaries where information from biological, physical, and chemical disciplines is combined for new insights. The Unsaturated Zone Interest Group (UZIG) is an organization that exists principally to promote multidisciplinary collaborations and the sharing of ideas, expertise, and technical assets. Here we summarize key findings from 14 papers, several of which originated from a meeting convened by UZIG in 2017 at the University of Florida in Gainesville titled “Land-Use Change, Climate Change, and Hydrologic Extremes: Unsaturated Zone Responses and Feedbacks.” This special section of Vadose Zone Journal contains multidisciplinary research in three general categories relevant to measuring and understanding unsaturated zone responses to changing land uses and climate: (i) unsaturated zone properties and processes; (ii) soil–plant–atmosphere interactions; and (iii) novel field sampling devices. A strong cross-cutting theme in these papers is the value of continuous monitoring data and ways of utilizing them to discover novel hydrologic, biologic, and pedologic information. As climatic and land-use conditions change and demands for resources and stresses on ecosystems continue to intensify, it is vital to improve our fundamental understanding of the processes at work in the unsaturated zone. Toward that goal, we discuss the need for improved ground-based unsaturated zone monitoring networks.

Vadose Zone Journal↗
USGS2014

Coal assessments and coal research in the Appalachian basin

Coal is one of our most important domestic energy resources, producing 37 percent of the Nation’s electricity in 2012. Coal mining within the Appalachian basin has been ongoing for three centuries and, cumulatively, the basin is the most productive coal region in the United States. In 2012, only the Powder River basin produced more coal than the Appalachian basin. Coal is the most important mined product within the basin, and research on the quality and quantity of the coal is one of the primary functions of the U.S. Geological Survey (USGS) and the State geological surveys of Alabama, Kentucky, Maryland, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. The USGS and the State geological surveys historically have worked together on coal research and assessment projects to achieve mutually beneficial science goals. The 2000 USGS coal resource assessment of the Appalachian basin (Northern and Central Appalachian Basin Coal Regions Assessment Team, 2001, USGS Professional Paper 1625–C) was done in close collaboration with scientists of the State geological surveys of Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia. Five of the top-producing coal beds and coal zones within the basin were quantitatively assessed, and results show that ample coal resources remain. Coal quality, not coal quantity, is the principal driver for coal production and use within the basin and will be for the foreseeable future. Cumulative coalbed-methane (CBM) production within the Appalachian basin has been about 2.3 trillion cubic feet (TCF), and most of the production has come from Alabama and Virginia (Milici and Polyak, this volume, chap. G.2). Significant CBM resources occur throughout the coal-producing States in the Appalachian basin, and commercial production is possible in all. State geological surveys are concentrating on mapping and correlating coal beds and coal zones and studying CBM potential and production. Both State surveys and the USGS are researching the potential for carbon dioxide sequestration in unmined coal beds and other geologic reservoirs. In addition, the State geological surveys continue their long-term collaboration with the USGS and provide coal stratigraphic data to the National Coal Resources Data System (NCRDS).

Appalachian basin↗
USGS2016

Technical Note: Harmonizing met-ocean model data via standard web services within small research groups

Work over the last decade has resulted in standardised web services and tools that can significantly improve the efficiency and effectiveness of working with meteorological and ocean model data. While many operational modelling centres have enabled query and access to data via common web services, most small research groups have not. The penetration of this approach into the research community, where IT resources are limited, can be dramatically improved by (1) making it simple for providers to enable web service access to existing output files; (2) using free technologies that are easy to deploy and configure; and (3) providing standardised, service-based tools that work in existing research environments. We present a simple, local brokering approach that lets modellers continue to use their existing files and tools, while serving virtual data sets that can be used with standardised tools. The goal of this paper is to convince modellers that a standardised framework is not only useful but can be implemented with modest effort using free software components. We use NetCDF Markup language for data aggregation and standardisation, the THREDDS Data Server for data delivery, pycsw for data search, NCTOOLBOX (MATLAB®) and Iris (Python) for data access, and Open Geospatial Consortium Web Map Service for data preview. We illustrate the effectiveness of this approach with two use cases involving small research modelling groups at NATO and USGS.

Ocean science and engineering↗
USGS2013

Understanding how social networking influences perceived satisfaction with conference experiences

Social networking is a key benefit derived from participation in conferences that bind the ties of a professional community. Building social networks can lead to satisfactory experiences while furthering participants' long- and short-term career goals. Although investigations of social networking can lend insight into how to effectively engage individuals and groups within a professional cohort, this area has been largely overlooked in past research. The present study investigates the relationship between social networking and satisfaction with the 10th Biennial Conference of Research on the Colorado Plateau using structural equation modelling. Results partially support the hypothesis that three dimensions of social networking – interpersonal connections, social cohesion, and secondary associations – positively contribute to the performance of various conference attributes identified in two focus group sessions. The theoretical and applied contributions of this paper shed light on the social systems formed within professional communities and resource allocation among service providers.

Annals of Leisure Research↗
USGS2010

On tide-induced Lagrangian residual current and residual transport: 2. Residual transport with application in south San Francisco Bay, California

The transports of solutes and other tracers are fundamental to estuarine processes. The apparent transport mechanisms are convection by tidal current and current-induced shear effect dispersion for processes which take place in a time period of the order of a tidal cycle. However, as emphasis is shifted toward the effects of intertidal processes, the net transport is mainly determined by tide-induced residual circulation and by residual circulation due to other processes. The commonly used intertidal conservation equation takes the form of a convection-dispersion equation in which the convective velocity is the Eulerian residual current, and the dispersion terms are often referred to as the phase effect dispersion or, sometimes, as the “tidal dispersion.” The presence of these dispersion terms is merely the result of a Fickian type hypothesis. Since the actual processes are not Fickian, thus a Fickian hypothesis obscures the physical significance of this equation. Recent research results on residual circulation have suggested that long-term transport phenomena are closely related to the Lagrangian residual current or the Lagrangian residual transport. In this paper a new formulation of an intertidal conservation equation is presented and examined in detail. In a weakly nonlinear tidal estuary the resultant intertidal transport equation also takes the form of a convection-dispersion equation without the ad hoc introduction of phase effect dispersion in a form of dispersion tensor. The convective velocity in the resultant equation is the first-order Lagrangian residual current (the sum of the Eulerian residual current and the Stokes drift). The remaining dispersion terms are important only in higher-order solutions; they are due to shear effect dispersion and turbulent mixing. There exists a dispersion boundary layer adjacent to shoreline boundaries. An order of magnitude estimate of the properties in the dispersion boundary layer is given. The present treatment of intertidal transport processes is illustrated by an analytical solution for an amphidromic system and by a numerical application in South San Francisco Bay, California. The present formulation reveals that the mechanism for long-term transport of solutes is mainly convection due to the Lagrangian residual current in the interior of a tidal estuary. This result also points out the weakness in the tidal dispersion formulation, and explains the large variability of the observed values for tidal dispersion coefficients. Further research on properties of the dispersion boundary layer is needed.

California↗
USGS2012

Sediment mobility and bed armoring in the St Clair River: insights from hydrodynamic modeling

The lake levels in Lake Michigan-Huron have recently fallen to near historical lows, as has the elevation difference between Lake Michigan-Huron compared to Lake Erie. This decline in lake levels has the potential to cause detrimental impacts on the lake ecosystems, together with social and economic impacts on communities in the entire Great Lakes region. Results from past work suggest that morphological changes in the St Clair River, which is the only natural outlet for Lake Michigan-Huron, could be an appreciable factor in the recent trends of lake level decline. A key research question is whether bed erosion within the river has caused an increase in water conveyance, therefore, contributed to the falling lake level. In this paper, a numerical modeling approach with field data is used to investigate the possibility of sediment movement in the St Clair River and assess the likelihood of morphological change under the current flow regime. A two-dimensional numerical model was used to study flow structure, bed shear stress, and sediment mobility/armoring over a range of flow discharges. Boundary conditions for the numerical model were provided by detailed field measurements that included high-resolution bathymetry and three-dimensional flow velocities. The results indicate that, without considering other effects, under the current range of flow conditions, the shear stresses produced by the river flow are too low to transport most of the coarse bed sediment within the reach and are too low to cause substantial bed erosion or bed scour. However, the detailed maps of the bed show mobile bedforms in the upper St Clair River that are indicative of sediment transport. Relatively high shear stresses near a constriction at the upstream end of the river and at channel bends could cause local scour and deposition. Ship-induced propeller wake erosion also is a likely cause of sediment movement in the entire reach. Other factors that may promote sediment movement, such as ice cover and dredging in the lower river, require further investigation.

St. Clair River↗
USGS2017

Introduction to “Global tsunami science: Past and future, Volume II”

Twenty-two papers on the study of tsunamis are included in Volume II of the PAGEOPH topical issue “Global Tsunami Science: Past and Future”. Volume I of this topical issue was published as PAGEOPH, vol. 173, No. 12, 2016 (Eds., E. L. Geist, H. M. Fritz, A. B. Rabinovich, and Y. Tanioka). Three papers in Volume II focus on details of the 2011 and 2016 tsunami-generating earthquakes offshore of Tohoku, Japan. The next six papers describe important case studies and observations of recent and historical events. Four papers related to tsunami hazard assessment are followed by three papers on tsunami hydrodynamics and numerical modelling. Three papers discuss problems of tsunami warning and real-time forecasting. The final set of three papers importantly investigates tsunamis generated by non-seismic sources: volcanic explosions, landslides, and meteorological disturbances. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.

Pure and Applied Geophysics↗
USGS2018

Drought and fire in the western USA: Is climate attribution enough?

Purpose of Review I sought to review the contributions of recent literature and prior foundational papers to our understanding of drought and fire. In this review, I summarize recent literature on drought and fire in the western USA and discuss research directions that may increase the utility of that body of work for twenty-first century application. I then describe gaps in the synthetic knowledge of drought-driven fire in managed ecosystems and use concepts from use-inspired research to describe potentially useful extensions of current work. Recent Findings Fire responses to climate, and specifically various kinds of drought, are clear, but vary widely with fuel responses to surplus water and drought at different timescales. Ecological and physical factors interact with human management and ignitions to create fire regime and landscape trajectories that challenge prediction. Summary The mechanisms by which the climate system affects regional droughts and how they translate to fire in the western USA need more attention to accelerate both forecasting and adaptation. However, projections of future fire activity under climate change will require integrated advances on both fronts to achieve decision-relevant modeling. Concepts from transdisciplinary research and coupled human-natural systems can help frame strategic work to address fire in a changing world.

Current Climate Change Reports↗
USGS1994

The applicability of terrestrial visitor impact management strategies to the protection of coral reefs

A dramatic expansion in nature-based tourism to tropical coastal destinations has occurred in the past 20 years. Tourism development, combined with intense recreational pressures, has irreversibly transformed and degraded many popular scenic natural environments. This paper examines the management of recreational impacts to coral reefs using Virgin Islands National Park as a case study. A review of terrestrial recreational ecology research explores the implications and potential applicability of some principal findings to the protection of coral reefs. Visitor impact management recommendations for the protection of coral reefs are offered. Managers can minimize coral reef recreational impacts by (1) restricting high-impact uses, (2) containing rather than dispersing recreational use, (3) encouraging the use of resistant environments, (4) teaching low-impact recreational practices, and (5) enforcing park rules and regulations.

Ocean and Coastal Management↗
USGS2003

The effects of summer flow augmentation on the migratory behavior and survival of juvenile Snake River fall Chinook salmon. Annual report 2003

This report summarizes results of research activities conducted in 2002 and years previous to aid in the management and recovery of fall chinook salmon Oncorhynchus tshawytscha in the Columbia River basin. The report is divided into self-standing chapters. For detailed summaries, we refer the reader to the abstracts given on the second page of each chapter. The Annual Reporting section includes information provided to fishery managers in-season and post-season, and it contains a detailed summary of life history and survival statistics on wild Snake River fall chinook salmon juveniles for the years 1992-2002. Peer-review publication remains a high priority of this research project, and it insures that our work meets high scientific standards. The Bibliography of Published Journal Articles section provides citations for peer-reviewed papers coauthored by personnel of project 199102900 that were written or published from 1998 to 2003.

Report↗
USGS1966

Some aspects of breeding biology of the blue-winged teal

The Blue-winged Teal ( Anas discors ) was the subject of one of the first publications dealing with the breeding biology of a species of North American waterfowl (Bennett, 1938). Recent studies of the nesting chronology, clutch size, and incubation period of this species include the works of Hochbaum (1944), Sowls (1955), and Glover (1956). The present paper supplements information on these aspects of breeding biology. Field work was done during the summers of 1961, 1962, and 1963 at the Delta Waterfowl Research Station (15 miles north of Portage la Prairie, Manitoba) which is adjacent to the Delta marsh at the south edge of Lake Manitoba. The climate in the area is subhumid. The mean annual temperature is 45.3°F and the annual precipitation is 20.1 inches at Winnipeg (60 miles ESE of Delta). The spring warming trend is variable and influences the time of spring arrival and the start of nesting of waterfowl (Sowls, 1955) and, as will be shown, the temperature may also influence the nesting chronology once a species has begun to nest. The daily mean temperatures and the daily lows at Winnipeg for the springs of 192 and 1963 are graphed in Figures 1 and 2. Daily records kept by nan Multer at Delta show that the temperatures there are similar to those at Winnipeg.

The Auk↗
USGS2012

Measuring the orthogonality error of coil systems

Recently, a simple method was proposed for the determination of pitch angle between two coil axes by means of a total field magnetometer. The method is applicable when the homogeneous volume in the centre of the coil system is large enough to accommodate the total field sensor. Orthogonality of calibration coil systems used for calibrating vector magnetometers can be attained by this procedure. In addition, the method can be easily automated and applied to the calibration of delta inclination–delta declination (dIdD) magnetometers. The method was tested by several independent research groups, having a variety of test equipment, and located at differing geomagnetic observatories, including: Nurmijärvi, Finland; Hermanus, South Africa; Ottawa, Canada; Tihany, Hungary. This paper summarizes the test results, and discusses the advantages and limitations of the method.

Proceedings of the XVth IAGA Workshop on Geomagnet↗
USGS2017

The evolution, approval and implementation of the U.S. Geological Survey Science Data Lifecycle Model

This paper details how the United States Geological Survey (USGS) Community for Data Integration (CDI) Data Management Working Group developed a Science Data Lifecycle Model, and the role the Model plays in shaping agency-wide policies. Starting with an extensive literature review of existing data Lifecycle models, representatives from various backgrounds in USGS attended a two-day meeting where the basic elements for the Science Data Lifecycle Model were determined. Refinements and reviews spanned two years, leading to finalization of the model and documentation in a formal agency publication . The Model serves as a critical framework for data management policy, instructional resources, and tools. The Model helps the USGS address both the Office of Science and Technology Policy (OSTP) for increased public access to federally funded research, and the Office of Management and Budget (OMB) 2013 Open Data directives, as the foundation for a series of agency policies related to data management planning, metadata development, data release procedures, and the long-term preservation of data. Additionally, the agency website devoted to data management instruction and best practices (www2.usgs.gov/datamanagement) is designed around the Model’s structure and concepts. This paper also illustrates how the Model is being used to develop tools for supporting USGS research and data management processes.

Journal of eScience Librarianship↗
USGS2014

Evaluation of development options for Alaska North Slope viscous and heavy oil

Current estimates of discovered viscous and heavy oil in Alaska’s North Slope are 12 billion barrels of oil-in-place and 12–18 billion barrels of oil-in-place, respectively (see Appendix 1 for conversion to SI units). Since the early 1990s to the end of 2010, cumulative viscous oil production has amounted to 150 million barrels, and there has been no commercial production of heavy oil. During the last three decades, the industry has been challenged to develop technologies to commercially produce these untapped oil resources in this Arctic environment. In this paper, the general locations and geologic properties of the viscous oil-bearing West Sak/Schrader Bluff and heavy oil-bearing Ugnu stratigraphic intervals are described first. The geologic variability within these deposits and the evolution of technology have forced an incremental development approach, requiring costly field testing at the pilot scale of innovative extraction techniques. Although viscous oil is currently produced, its development is not mature, and firms appear to be still spending large sums on new approaches to improve recovery. The analysis specifies a representative viscous oil project and then applies a “real options” framework using simulation to determine whether the risked expected project value is sufficient to fund required expenditures on extraction process research and field testing. Computations show available field test funds to be highly sensitive to the operator’s hurdle rate of return as well as the range in magnitude of potential State revenues. The contribution of the paper is solving this problem using an approach where the extreme low return and high scenarios need only be specified, and where the uncertainties are modeled with beta distributions based on historical data or expert opinion.

Alaska↗