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At least 145 records · Page 8Linked to original sources
USGS2018

Recent advances in environmental flows science and water management—Innovation in the Anthropocene

The implementation of environmental flow regimes offers a promising means to protect and restore riverine, wetland and estuarine ecosystems, their critical environmental services and cultural/societal values. This Special Issue expands the scope of environmental flows and water science in theory and practice, offering 20 papers from academics, agency researchers and non‐governmental organisations, each with fresh perspectives on the science and management of environmental water allocations. Contributions confront the grand challenge for environmental flows and water management in the Anthropocene—the urgent need for innovations that will help to sustain the innate resilience of social–ecological systems under dynamic and uncertain environmental and societal futures. Basin‐scale and regional assessments of flow requirements mark a necessary advance in environmental water science in the face of rapid changes in water‐resource management activities worldwide (e.g. increases in dams, diversions, retention and reuse). Techniques for regional‐scale hydrological and ecohydrological modelling support ecological risk assessment and identification of priority flow management and river restoration actions. Changing flood–drought cycles, long‐term climatic shifts and associated effects on hydrological, thermal and water quality regimes add enormous uncertainty to the prediction of future ecological outcomes, regardless of environmental water allocations. An improved capacity to predict the trajectories of ecological change in rivers degraded by legacies of past impact interacting with current conditions and future climate change is essential. Otherwise, we risk unrealistic expectations from restoration of river and estuarine flow regimes. A more robust, dynamic and predictive approach to environmental water science is emerging. It encourages the measurement of process rates (e.g. birth rate, colonisation rate) and species traits (e.g. physiological requirements, morphological adaptations) as well as ecosystem states (e.g. species richness, assemblage structure), as the variables representing ecological responses to flow variability and environmental water allocations. Another necessary development is the incorporation of other environmental variables such as water temperature and sedimentary processes in flow–ecological response models. Based on contributions to this Special Issue, several recent compilations and the wider literature, we identify six major scientific challenges for further exploration, and seven themes for advancing the management of environmental water. We see the emerging frontier of environmental flows and water science as urgent and challenging, with numerous opportunities for reinvigorated science and methodological innovation in the expanding enterprise of environmental water linked to ecological sustainability and social well‐being.

Freshwater Biology↗
USGS2005

TREMOR: A wireless MEMS accelerograph for dense arrays

The ability of a strong-motion network to resolve wavefields can be described on three axes: frequency, amplitude, and space. While the need for spatial resolution is apparent, for practical reasons that axis is often neglected. TREMOR is a MEMS-based accelerograph using wireless Internet to minimize lifecycle cost. TREMOR instruments can economically augment traditional ones, residing between them to improve spatial resolution. The TREMOR instrument described here has dynamic range of 96 dB between ??2 g, or 102 dB between ??4 g. It is linear to ???1% of full scale (FS), with a response function effectively shaped electronically. We developed an economical, very low noise, accurate (???1%FS) temperature compensation method. Displacement is easily recovered to 10-cm accuracy at full bandwidth, and better with care. We deployed prototype instruments in Oakland, California, beginning in 1998, with 13 now at mean spacing of ???3 km - one of the most densely instrumented urban centers in the United States. This array is among the quickest in returning (PGA, PGV, Sa) vectors to ShakeMap, ???75 to 100 s. Some 13 events have been recorded. A ShakeMap and an example of spatial variability are shown. Extensive tests of the prototypes for a commercial instrument are described here and in a companion paper. ?? 2005, Earthquake Engineering Research Institute.

Earthquake Spectra↗
USGS2009

Extensive coral mortality in the US Virgin Islands in 2005/2006: A review of the evidence for synergy among thermal stress, coral bleaching and disease

In the summer/fall of 2005, extensive coral bleaching on reefs in the US Virgin Islands (USVI) was associated with sea water temperatures exceeding 30°C. Almost all coral species bleached, including Acropora palmata , which bleached for the first time on record in the USVI. As water temperatures cooled, corals began to regain their normal coloration. However, a severe disease outbreak then occurred on deeper, non-acroporid reefs. The disease demonstrated signs consistent with white plague. Monitoring of coral cover along previously established long-term transects on several reefs in St. John and St. Croix was intensified. Data on bleaching and disease were collected before, during and after this bleaching/disease episode. Average coral cover declined by over 50%, from 21.4% to 10.3% at the long-term study sites, within one year of the onset of bleaching, declining further to 8.3% after two years. This loss of coral cover was greater than from all other stressors affecting the USVI reefs in preceding years, and no significant recovery is evident. Disease prevalence increased on bleached A. palmata colonies that were being monitored as well as on the colonies of other species on the deeper reefs. Bleached A. palmata colonies had more disease (primarily white pox and other un-described diseases) than unbleached colonies. The non-acroporid corals that bleached most severely suffered the highest mortality from disease. Although the research summarized in this paper is not conclusive, the results suggest that high water temperatures lead to bleaching, which weakens corals and makes them more vulnerable to diseases.

U.S. Virgin Islands↗
USGS2008

Ecology in the information age: Patterns of use and attrition rates of internet-based citations in ESA journals, 1997–2005

As the amount of information available on the internet has increased, so too has the number of citations to network-accessible information in scholarly research. We searched all papers in four Ecological Society of America journals from 1997 to 2005 for articles containing a citation to material on the internet. We then tested the links to determine whether the information cited in the paper was still accessible. We identified 877 articles that contained at least one link to information on the internet and a total of 2100 unique links. The majority of these citations were based on an object's location (Uniform Resource Locator; 77%), whereas the rest were based on an object's identity (eg Digital Object Identifier, GenBank Accession number). We found that 19–30% of the location-based links were unavailable and that there was a positive relationship between the age of an article and the probability of the link being inactive. Using an internet search engine, we recovered 72–84% of the lost information, leaving a total of 6.2% of the total citations unavailable. Our results highlight the problem of persistence of information stored on the world wide web and we include recommendations for minimizing this problem.

Frontiers in Ecology and the Environment↗
USGS1964

Sedimentology: general introduction and definitions : fluvial sediment and channel morphology

Sedimentology, the study of sedimentary rocks and the processes by which they are formed, includes and is related to a large number of phenomena. Sedimentology includes the five fundamental processes defined by the term sediaentation --weathering, erosion, transportation, deposition and diagenesis. Sedimentology shares with geomorphology the study of the surface features of the earth. Sedimentology also shares with hydrology the study of river.--channels. River channels are formed in part or in total as a result of flowing water and sediment transport, commonly called the "work of the rivers." This survey of published literature was made to aid in arriving at definitions which would be acceptable to, and representative of, a majority of professional personnel actively engaged in laboratory and field investigations related to the "work of the river." The definitions in this list are intended to explain the terms used in studies of fluvial sediment and channel morphology. No set of definitions can expect universal acceptance, however, i t is hoped that this compilation will be considered a summary and synthesis of present and past usage and that it will serve as a starting point for future usage. Multiple references are cited from textbooks, glossaries and dictionaries, scientific journals and u.s. Government publications. To obtain a mutual understanding and enhance precision, many of the proposed definitions are a composite of those selected from papers or reports covering research studies and field investigations. A draft of this glossary has been reviewed by a group of interested personnel. The results of this review have been carefully considered and the originally-suggested definitions have been revised accordingly, resulting in the present compilation. R. G. Wolff, with the help of Mrs. v. Blatcher, carried out the literature search and compilation of terms and the review results. Paul c. Benedict approved or composed the definitions as presented in this report.

Open-File Report↗
USGS2006

USGS Abandoned Mine Lands Research Presented at the NAAMLP Meeting in Billings, Mont., Sept. 25, 2006

The following talk was an invited presentation given at the National Association of Abandoned Mine Lands Programs meeting in Billings, Montana on Sept. 25, 2006. The objective of the talk was to outline the scope of the U.S. Geological Survey research, past, present and future, in the area of abandoned mine research. Two large Professional Papers have come out of our AML studies: Nimick, D.A., Church, S.E., and Finger, S.E., eds., 2004, Integrated investigations of environmental effects of historical mining in the Basin and Boulder mining districts, Boulder River watershed, Jefferson County, Montana: U.S. Geological Survey Professional Paper 1652, 524 p., 2 plates, 1 DVD, URL: http://pubs.er.usgs.gov/usgspubs/pp/pp1652 Church, S.E., von Guerard, Paul, and Finger, S.E., eds., 2006, Integrated Investigations of Environmental Effects of Historical Mining in the Animas River Watershed, San Juan County, Colorado: U.S. Geological Survey Professional Paper 1651, 1,096 p., 6 plates, 1 DVD (in press). Additional publications and links can be found on the USGS AML website at URL: http://amli.usgs.gov/ or are accessible from the USGS Mineral Resource Program website at URL: http://minerals.usgs.gov/.

Open-File Report↗
USGS2019

Methods for installation, removal, and downloading data from the temperature profiling probe (TROD)

This document provides a brief method overview on the deployment and removal of the temperature profiling probe developed by the U.S. Geological Survey (USGS) in 2015 and referred to as SensorRod or temperature rod (TROD). The TROD is suitable for short- to long-term deployments (days to years) for evaluating thermal gradients in soils and sediments beneath surface water. Applications include evaluating exchange between groundwater and surface water, seepage losses in agricultural canals, infiltration on hillslopes, and timing of snowmelt and runoff. The temperature sensors inside the TROD are iButtons and are meant to be replaceable when needed. The housing is water tight and is made of schedule 80 PVC pipe. Sensor intervals are flexible and can be built to specific applications. A joint patent (U.S 10/180,360.) and license agreement between the USGS and Alpha Mach for the TROD design was obtained in 2019, and a paper in Water Resource Research describes the design and testing (Naranjo and Turcotte, 2015).

Open-File Report↗
USGS2008

Using open hole and cased-hole resistivity logs to monitor gas hydrate dissociation during a thermal test in the mallik 5L-38 research well, Mackenzie Delta, Canada

Gas hydrates, which are naturally occurring ice-like combinations of gas and water, have the potential to provide vast amounts of natural gas from the world's oceans and polar regions. However, producing gas economically from hydrates entails major technical challenges. Proposed recovery methods such as dissociating or melting gas hydrates by heating or depressurization are currently being tested. One such test was conducted in northern Canada by the partners in the Mallik 2002 Gas Hydrate Production Research Well Program. This paper describes how resistivity logs were used to determine the size of the annular region of gas hydrate dissociation that occurred around the wellbore during the thermal test in the Mallik 5L-38 well. An open-hole logging suite, run prior to the thermal test, included array induction, array laterolog, nuclear magnetic resonance and 1.1-GHz electromagnetic propagation logs. The reservoir saturation tool was run both before and after the thermal test to monitor formation changes. A cased-hole formation resistivity log was run after the test.Baseline resistivity values in each formation layer (Rt) were established from the deep laterolog data. The resistivity in the region of gas hydrate dissociation near the wellbore (Rxo) was determined from electromagnetic propagation and reservoir saturation tool measurements. The radius of hydrate dissociation as a function of depth was then determined by means of iterative forward modeling of cased-hole formation resistivity tool response. The solution was obtained by varying the modeled dissociation radius until the modeled log overlaid the field log. Pretest gas hydrate production computer simulations had predicted that dissociation would take place at a uniform radius over the 13-ft test interval. However, the post-test resistivity modeling showed that this was not the case. The resistivity-derived dissociation radius was greatest near the outlet of the pipe that circulated hot water in the wellbore, where the highest temperatures were recorded. The radius was smallest near the center of the test interval, where a conglomerate section with low values of porosity and permeability inhibited dissociation. The free gas volume calculated from the resistivity-derived dissociation radii yielded a value within 20 per cent of surface gauge measurements. These results show that the inversion of resistivity measurements holds promise for use in future gas hydrate monitoring. ?? 2008 Society of Petrophysicists and Well Log Analysts. All rights reserved.

Conference Paper↗
USGS2007

A new focus on groundwater-seawater interactions

In summary, the papers in this volume present research by those working from the marine and the terrestrial sides of issues related to SGD and groundwater-seawater interactions. The first part of this paper provides an introduction and background information on the subject of SGD and groundwater-seawater interactions. The second part of this paper provides an overview of the 38 symposium papers and places them in context according to the methods used to quantify SGD. The papers presented in this volume describe important contributions to the literature and document a variety of investigative approaches applied over a range of conditions at locations across the globe.

Conference Paper↗
USGS1993

Proceedings of the first biennial conference of research in Colorado Plateau National Parks

The 19 papers in this volume were selected from the 46 presentations given at the First Biennial Conference on Research in Colorado Plateau National Parks. The overall theme for this meeting was research, inventory, and monitoring in National Park Service units on the Colorado Plateau. The conference, held in Flagstaff Arizona, on 22-25 July 1991, was sponsored by the National Park Service Cooperative Park Studies Unit, Northern Arizona University, and the Petrified Forest, Zion, and Grand Canyon natural history associations.

Utah;Colorado;Arizona;New Mexico↗
USGS2019

Amphibian conservation in the Anthropocene

Research is necessary to identify patterns in nature, to understand how a system functions, and to make predictions about the future state of an ecosystem. Applied research in conservation biology can identify effective strategies to maintain biodiversity, though many papers end with the conclusion that more research is needed. However, more research does not necessarily lead to solutions. We use the ongoing global decline of amphibians as a salient example to highlight limitations in current conservation research, and to focus on finding solutions which are directly relevant for conservation. While research has been conducted since declines were first detected in the 1990s, outside a few specific examples, little progress in conservation has been achieved. We suggest that the case of amphibian declines is relevant to conservation science in general, as the current paradigm for conservation is that management is planned after research is completed; research and management are not effectively (and not directly) connected. This disconnect illustrates the knowledge-action divide which has been identified as a serious deficiency in conservation. Accordingly, we use this introductory paper to the Special Issue (Amphibian conservation in the Anthropocene: Progress and challenges) to describe amphibians as a conservation dilemma, and to make the case for a different, more pragmatic, and more solutions-focused view of conservation research.

Kansas, Oklahoma↗
USGS2024

GeoAI for science and the science of GeoAI

This paper reviews trends in GeoAI research and discusses cutting-edge ad- vances in GeoAI and its roles in accelerating environmental and social sciences. It ad- dresses ongoing attempts to improve the predictability of GeoAI models and recent re- search aimed at increasing model explainability and reproducibility to ensure trustworthy geospatial findings. The paper also provides reflections on the importance of defining the "science" of GeoAI in terms of its fundamental principles, theories, and methods to ensure scientific rigor, social responsibility, and lasting impacts.

Journal of Spatial Information Science↗
USGS2012

Radio telemetry equipment and applications for carnivores

Radio-telemetry was not included in the first comprehensive manual of wildlife research techniques (Mosby 1960) because the first published papers were about physiological wildlife telemetry (LeMunyan et al. 1959) and because research using telemetry in field ecology was just being initiated (Marshall et al. 1962; Cochran and Lord 1963). Among the first uses of telemetry to study wildlife, however, was a study of carnivores (Craighead et al. 1963), and telemetry has become a common method for studying numerous topics of carnivore biology. Our goals for this chapter are to provide basic information about radio-telemetry equipment and procedures. Although we provide many references to studies using telemetry equipment and methods, we recommend Kenward's (2001) comprehensive book, A manual of wildlife radio tagging for persons who are unfamiliar with radio-telemetry, Fuller et al. (2005), and Tomkiewicz et al. (2010). Compendia of uses of radio-telemetry in animal research appear regularly as chapters in manuals (Cochran 1980; Samuel and Fuller 1994), in books about equipment, field procedures, study design, and applications (Amlaner and Macdonald 1980; Anderka 1987; Amlaner 1989; White and Garrott 1990; Priede and Swift 1992; Kenward 2001; Millspaugh and Marzluff 2001; Mech and Barber 2002), and in reviews highlighting new developments (Cooke et al. 2004; Rutz and Hays 2009; Cagnacci et al. 2010). Some animal telemetry products and techniques have remained almost unchanged for years, but new technologies and approaches emerge and replace previously available equipment at an increasing pace. Here, we emphasize recent studies for which telemetry was used with carnivores.

Book chapter↗
USGS1985

Rock mechanics observations pertinent to the rheology of the continental lithosphere and the localization of strain along shear zones

Emphasized in this paper are the deformation processes and rheologies of rocks at high temperatures and high effective pressures, conditions that are presumably appropriate to the lower crust and upper mantle in continental collision zones. Much recent progress has been made in understanding the flexure of the oceanic lithosphere using rock-mechanics-based yield criteria for the inelastic deformations at the top and base. At mid-plate depths, stresses are likely to be supported elastically because bending strains and elastic stresses are low. The collisional tectonic regime, however, is far more complex because very large permanent strains are sustained at mid-plate depths and this requires us to include the broad transition between brittle and ductile flow. Moreover, important changes in the ductile flow mechanisms occur at the intermediate temperatures found at mid-plate depths. Two specific contributions of laboratory rock rheology research are considered in this paper. First, the high-temperature steady-state flow mechanisms and rheology of mafic and ultramafic rocks are reviewed with special emphasis on olivine and crystalline rocks. Rock strength decreases very markedly with increases in temperature and it is the onset of flow by high temperature ductile mechanisms that defines the base of the lithosphere. The thickness of the continental lithosphere can therefore be defined by the depth to a particular isotherm Tc above which (at geologic strain rates) the high-temperature ductile strength falls below some arbitrary strength isobar (e.g., 100 MPa). For olivine Tc is about 700??-800??C but for other crustal silicates, Tc may be as low as 400??-600??C, suggesting that substantial decoupling may take place within thick continental crust and that strength may increase with depth at the Moho, as suggested by a number of workers on independent grounds. Put another way, the Moho is a rheological discontinuity. A second class of laboratory observations pertains to the general phenomenon of ductile faulting in which ductile strains are localized into shear zones. Ductile faults have been produced in experiments of five different rock types and is generally expressed as strain softening in constant-strain-rate tests or as an accelerating-creep-rate stage at constant differential stress. A number of physical mechanisms have been identified that may be responsible for ductile faulting, including the onset of dynamic recrystallization, phase changes, hydrothermal alteration and hydrolytic weakening. Microscopic evidence for these processes as well as larger-scale geological and geophysical observations suggest that ductile faulting in the middle to lower crust and upper mantle may greatly influence the distribution and magnitudes of differential stresses and the style of deformation in the overlying upper continental lithosphere.

Tectonophysics↗
USGS1981

Proceedings of Conference XIII, evaluation of regional seismic hazards and risk

The participants in the conference concluded that a great deal of useful research has been performed in the national Earthquake Hazards Reduction Program by USGS and non-USGS scientists and engineers and that the state-of-knowledge concerning the evaluation of seismic hazards and risk has been advanced substantially. Many of the technical issues raised during the conference are less controversial now because of new information and insights gained during the first three years of the expanded research program conducted under the Earthquake Hazards Reduction Act. Utilization of research results by many groups of users has also improved during this period and further improvement in utilization appears likely. Additional research is still required to resolve more completely the many complex technical issues summarized above and described in the papers contained in the proceedings. Improved certainty of research results on the evaluation of regional seismic hazards and risk is required before full utilization can be made by state and local governments who deal. with people frequently having a different perception of the hazard and its risk to them than that perceived by scientists or engineers. Each of the papers contained in the proceedings contain throughtful recommendations for improving the state-of-knowledge. Two papers, in particular, focussed on this particular theme. The first was presented by Lynn Sykes in the Geologic Keynote Address. He identified geographic areas throughout the world which may be considered as counterparts or analogues of seismic zones in the United States. He concluded that much can be learned about prediction, tectonic settings, earthquake hazards, and earthquake risk for sites in the United States by studying their tectonic analogues in other countries. The second paper was presented by John Blume in the Engineering Keynote Address. He suggested 20 specific research topics that, in his opinion, will significantly advance the state-of-the-art in earthquakeresistant design. The papers by Sykes and Blume are presented in the front of the proceedings.

Open-File Report↗