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At least 379 records · Page 21Linked to original sources
USGS1988

Three decades of geochronologic studies in the New England Appalachians

Over the past 30 years, both isotope geochronology and plate tectonics grew from infancy into authoritative disciplines in the geological sciences. Previously, mountain systems like the Appalachians had been viewed almost entirely in the context of the classical geosyncline, implying a gradualism in stratigraphic and structural change throughout the orogen. Age control, determined largely from distant fossiliferous strata, was unabashedly carried to high-grade metamorphic rocks based only on lithological correlations. With the new concepts in tectonics came the realization that abrupt breaks in stratigraphy and structure occur in many cases at the boundaries of lithotectonic zones. Fortunately, the new techniques of isotope geochronology could be brought to bear directly on the rocks of the immediate study area. This paper chronicles some of the major contributions to the geology of the New England Appalachians that resulted from these efforts during the past three decades. In tracing the history of geochronologic research, one encounters an increasingly sophisticated approach to the analytical and interpretive aspects of the discipline. Today, the geochronologist can, under optimum conditions, constrain the age of stratigraphic units, igneous activity, deformation, and metamorphism with accuracy that is capable of resolving fine structure within individual orogenic pulses. He participates in full partnership with other colleagues of the science in unravelling the mysteries of mountain building. Several of the topical problems of New England geology in which geochronology played a key role include (1) the recognition and delineation of Avalonia as a Late Proterozoic eastern basement distinct from more western terranes, (2) the dating of the White Mountain Plutonic-Volcanic Suite, a Mesozoic igneous event spanning 100 m.y., and (3) the temporal and spatial separation of structural and metamorphic features imprinted by the Taconic and Acadian orogenies. The existing geochronology is summarized into a map and table emphasizing the temporal construction of the New England Appalachians. By using lithotectonic zones as the building blocks of the orogen, seven such zones are defined in terms of pre-, syn-, and post-assembly geologic history. From west to east, these lithotectonic zones are (1) Berkshire-Green Mountain, (2) Rowe-Hawley, (3) Connecticut Valley, (4) Bronson Hill, (5) Kearsarge-Central Maine, (6) Tatnic Hill-Nashoba, and (7) Avalonia. Avalonia is further divided into three subzones, Hope Valley, Esmond-Dedham, and Penobscot Bay, which themselves may have had distinct origins and assembly histories. The boundaries between these zones are faults in most cases, some of which may have had recurring movement to further complicate any plate-tectonic scenario. A delineation of underlying Grenvillian, Chain Lakes, and Avalonian basement is also attempted, which now can make use of isotopes in igneous rocks as petrogenetic indicators to supplement the rare occurrences of basement outcrop within mobile zones of the orogen. The belt of Permian thermal disturbance within the Kearsarge-Central Maine zone is hypothesized to reflect rapid rebound following compressional thickening of underlying Avalonian basement during the Alleghanian orogeny.

Geological Society of America Bulletin↗
USGS2020

Pesticide mixtures show potential toxicity to aquatic life in U.S. streams, water years 2013-2017

During water years (WY) 2013–2017, the U.S. Geological Survey, National Water-Quality Assessment (NAWQA) Project, sampled the National Water Quality Network – Rivers and Streams (NWQN) year-round and reported on 221 pesticides at 72 sites across the United States in agricultural, developed, and mixed land use watersheds. The Pesticide Toxicity Index (PTI) was used to estimate the potential chronic and acute toxicity to three taxonomic groups – fish, cladocerans, and benthic invertebrates. For invertebrates (either cladocerans, benthic invertebrates, or both), the maximum PTI score exceeded the predicted acute toxicity screening level at 18 of the 72 sites (25%) at some point during WY 2013–2017. The predicted toxicity of a single pesticide compound was found to overwhelm the toxicity of other pesticides in the mixtures after concentrations were toxicity weighted. For this study, about 71%, 72%, and 92% of the Fish-, Cladoceran-, and Benthic Invertebrate-PTI scores, respectively, had one pesticide compound primarily contributing to sample potential toxicity (>50%). There were 17 (13 insecticides, 2 herbicides, 1 fungicide, and 1 synergist) of the 221 pesticide compounds analyzed that were the primary drivers of potential toxicity in each water sample in which the PTI and TUmax (toxic unit score for the pesticide that makes the single largest contribution to the PTI) scores were above predicted chronic (>0.1) or acute (>1) toxicity levels for one of the three taxa. For cladocerans and benthic invertebrates, the drivers of predicted chronic (>0.1) and acute (>1) PTIs were mostly insecticides. For cladocerans, the pesticide compounds driving the PTI scores were bifenthrin, carbaryl, chlorpyrifos, diazinon, dichlorvos, dicrotophos, diflubenzuron, flubendiamide, and tebupirimfos. For benthic invertebrates, atrazine (an herbicide), as well as the insecticides – bifenthrin, carbaryl, carbofuran, chlorpyrifos, diazinon, dichlorvos, fipronil, imidacloprid, and methamidophos – were the drivers of predicted toxicity. For fish, there were three pesticide types that contributed the most to predicted chronic (>0.1) PTIs – acetochlor, an herbicide; carbendazim, a fungicide degradate; and piperonylbutoxide, a synergist.

Science of the Total Environment↗
USGS2020

Molecular identification of water-extractable organic carbon from thermally heated soils: C-13 NMR and accurate mass analyses find benzene and pyridine carboxylic acids

To simulate the effects of wildfire on the combustion process in soils and their potential to leach organic compounds into streams and groundwater, mineral soil samples were heated at temperatures of 150–550 °C. Then, the soils were leached with deionized water, filtered, and analyzed for dissolved organic carbon. The water extract was concentrated by both XAD-8 and XAD-4 resins and analyzed by C-13 nuclear magnetic resonance and liquid chromatography time-of-flight mass spectrometry. Approximately 15–20% of the water-extractable organic carbon was identified as benzene dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acid isomers, commonly called BPCAs. Also identified were isomers of pyridine dicarboxylic acids and tricarboxylic acids (PCAs). The conversion of soil organic carbon to BPCAs occurs at 250 °C and reaches a maximum between 350 and 450 °C. At higher temperatures (>450 °C), the BPCA concentrations decrease, suggesting decarboxylation and conversion to carbon dioxide and water. This is the first report of BPCAs and PCAs in water-extractable organic carbon from thermally altered soil and suggest that these compounds are possible candidates for further water-quality studies in watersheds affected by wildfire. Finally, BPCAs and PCAs could contribute to the black carbon and nitrogen in seawater and are worthy of future investigation.

Environmental Science and Technology↗
USGS2013

Association of toxin-producing Clostridium botulinum with the macroalga Cladophora in the Great Lakes

Avian botulism, a paralytic disease of birds, often occurs on a yearly cycle and is increasingly becoming more common in the Great Lakes. Outbreaks are caused by bird ingestion of neurotoxins produced by Clostridium botulinum, a spore-forming, gram-positive, anaerobe. The nuisance, macrophytic, green alga Cladophora (Chlorophyta; mostly Cladophora glomerata L.) is a potential habitat for the growth of C. botulinum. A high incidence of botulism in shoreline birds at Sleeping Bear Dunes National Lakeshore (SLBE) in Lake Michigan coincides with increasingly massive accumulations of Cladophora in nearshore waters. In this study, free-floating algal mats were collected from SLBE and other shorelines of the Great Lakes between June and October 2011. The abundance of C. botulinum in algal mats was quantified and the type of botulism neurotoxin (bont) genes associated with this organism were determined by using most-probable-number PCR (MPN-PCR) and five distinct bont gene-specific primers (A, B, C, E, and F). The MPN-PCR results showed that 16 of 22 (73%) algal mats from the SLBE and 23 of 31(74%) algal mats from other shorelines of the Great Lakes contained the bont type E (bont/E) gene. C. botulinum was present up to 15 000 MPN per gram dried algae based on gene copies of bont/E. In addition, genes for bont/A and bont/B, which are commonly associated with human diseases, were detected in a few algal samples. Moreover, C. botulinum was present as vegetative cells rather than as dormant spores in Cladophora mats. Mouse toxin assays done using supernatants from enrichment of Cladophora containing high densities of C. botulinum (>1000 MPN/g dried algae) showed that Cladophora-borne C. botulinum were toxin-producing species (BoNT/E). Our results indicate that Cladophora provides a habitat for C. botulinum, warranting additional studies to better understand the relationship between this bacterium and the alga, and how this interaction potentially contributes to botulism outbreaks in birds.

Great Lakes↗
USGS2024

Habitat use of anadromous and amphidromous sturgeons in North America: A systematic review

Sturgeons are among the most endangered fishes in the world. Identifying habitat use characteristics to inform restoration projects is crucial for recovery. However, small sample sizes, inadequate replication of studies, and limited spatial extents complicate our ability to effectively apply the findings of single studies to endangered species conservation across the larger riverscape. We synthesized information from amphidromous and anadromous sturgeons in North America to identify species-specific knowledge gaps and conduct a quantitative comparison of species–habitat relationships. We provided a qualitative summary of substrate use and synthesized estimates of depth and velocity during spawning and non-spawning activity. Generalized patterns among species were identified, such as spawning in fast water on hard substrate and then using slow water with soft substrate areas when not spawning. We noted species-specific variability during spawning that may be attributed to historical maximum length, egg characteristics, and watershed features. This study provides some of the first estimates of habitat use that can be adapted for many populations. Results can contribute to empirically grounded decision-support tools used to prioritize information needs for recovery.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2024

Global survey of paleo-bedforms on Mars

Sedimentary processes on Mars have contributed to a plethora of landforms, both ancient and modern. Many of these are aeolian- or fluvial-formed constructs that meet the morphologic criteria for dunes and ripples but are clearly lithified and part of the rock record. This study conducted a survey of Mars using data returned from the High Resolution Imaging Science Experiment (HiRISE) to characterize the spatial distribution, origin, and geologic context of these preserved ancient bedforms, termed here as paleo-bedforms. The most compelling class include organized groups of 2–80-m-tall, crescentic to transverse features spaced at 100–1000 m wavelengths at Apollinaris Sulci, Valles Marineris, and other low-latitude sites. These morphologies along with superposed craters, boulders, and fractures led to the interpretation that these are highly lithified, friable, and partially eroded ancient aeolian dunes. In addition to lithified dunes, other remnants of ancient bedforms include examples in which the dune was completely removed, leaving a shallow depression in a crescentic outline as dune cast pits. The most widespread occurrences of paleo-bedforms show crest-to-crest wavelengths (10–80 m), heights (∼1–4 m), and morphologies consistent with lower-order bedforms of megaripples or transverse aeolian ridges. Paleo-megaripple fields in Arcadia Planitia, Hellas Planitia, Terra Sirenum, and other locations exhibit a progression of degraded morphologies, with crests showing signs of rounding, pitting, or fracturing, while heights and slopes are diminished due to erosion. Most rare are the paleo-bedforms in the fluvial bedform class at Lethe Vallis and Holden crater, as they occur along the path of proposed ancient flooding events. More enigmatic paleo-bedform candidates occur concentrated along the steep Valles Marineris and Noctis Labyrinthus wall slopes. These intermediate-sized, arcuate landforms that resemble transverse climbing dunes are heavily cratered, but they may align perpendicular or oblique to the local gradient, perhaps formed by wall slope winds and slope creep. The bedforms are unlike most ancient terrestrial aeolian or fluvial bedform systems, which are typically preserved only as truncated members of stratigraphic sections. Episodes of burial and exhumation by various geologic units (e.g., the Medusae Fossae Formation, pyroclastic units, lava flows, dust) are notable, whereas other bedforms appear to have been stabilized and partially lithified in place without burial. Ongoing agents of mass wasting, aeolian abrasion, and cryo-driven processes have contributed to the exhumation, erosion, and weathered appearance of paleo-bedforms, and a spectrum of degradation states was observed. Collectively, we report a diverse variety of ancient sedimentary bedforms preserved across Mars, with implications about paleoclimates and landscape evolution on Mars.

Geomorphology↗
USGS2004

Cassini observations of Io's visible aurorae

More than 500 images of Io in eclipse were acquired by the Cassini spacecraft in late 2000 and early 2001 as it passed through the jovian system en route to Saturn (Porco et al., 2003, Science 299, 1541-1547). Io's bright equatorial glows were detected in Cassini's near-ultraviolet filters, supporting the interpretation that the visible emissions are predominantly due to molecular SO2. Detailed comparisons of laboratory SO2 spectra with the Cassini observations indicate that a mixture of gases contribute to the equatorial emissions. Potassium is suggested by new detections of the equatorial glows at near-infrared wavelengths from 730 to 800 nm. Neutral atomic oxygen and sodium are required to explain the brightness of the glows at visible wavelengths. The molecule S2 is postulated to emit most of the glow intensity in the wavelength interval from 390 to 500 nm. The locations of the visible emissions vary in response to the changing orientation of the external magnetic field, tracking the tangent points of the jovian magnetic field lines. Limb glows distinct from the equatorial emissions were observed at visible to near-infrared wavelengths from 500 to 850 nm, indicating that atomic O, Na, and K are distributed across Io's surface. Stratification of the atmosphere is demonstrated by differences in the altitudes of emissions at various wavelengths: SO2 emissions are confined to a region close to Io's surface, whereas neutral oxygen emissions are seen at altitudes that reach up to 900 km, or half the radius of the satellite. Pre-egress brightening demonstrates that light scattered into Jupiter's shadow by gases or aerosols in the giant planet's upper atmosphere contaminates images of Io taken within 13 minutes of entry into or emergence from Jupiter's umbra. Although partial atmospheric collapse is suggested by the longer timescale for post-ingress dimming than pre-egress brightening, Io's atmosphere must be substantially supported by volcanism to retain auroral emissions throughout the duration of eclipse. ?? 2004 Elsevier Inc. All rights reserved.

Icarus↗
USGS2001

Analytical data for waters of the Harvard Open Pit, Jamestown Mine, Tuolumne County, California, March 1998-September 1999

The Jamestown mine is located in the Jamestown mining district in western Tuolumne County, California (see Fig. 1). This district is one of many located on or near the Melones fault zone, a major regional suture in the Sierra Nevada foothills. The districts along the Melones fault comprise the Mother Lode gold belt (Clark, 1970). The Harvard pit is the largest of several open pits mined at the Jamestown site by Sonora Mining Corporation between 1986 and 1994 (Fig. 2; Algood, 1990). It is at the site of an historical mine named the Harvard that produced about 100,000 troy ounces of gold, mainly between 1906 and 1916 (Julihn and Horton, 1940). Sonora Mining mined and processed about 17,000,000 short tons of ore, with an overall stripping ratio of about 4.5:1, yielding about 660,000 troy ounces of gold (Nelson and Leicht, 1994). Most of this material came from the Harvard pit, which attained dimensions of about 2700 ft (830 m) in length, 1500 ft (460 m) in width, and 600 ft (185 m) in depth. The bottom of the pit is at an elevation of 870 ft (265 m). Since mining operations ceased in mid-1994, the open pit has been filling with water. As of November, 2000, lake level had reached an elevation of about 1170 ft (357 m). Water quality monitoring data gathered after mine closure showed rising levels of arsenic, sulfate, and other components in the lake, with particularly notable increases accompanying a period of rapid filling in 1995 (County of Tuolumne, 1998). The largest potential source for arsenic in the vicinity of the Harvard pit is arsenian pyrite, the most abundant sulfide mineral related to gold mineralization. A previous study of weathering of arsenian pyrite in similarly mineralized rocks at the Clio mine, in the nearby Jacksonville mining district, showed that arsenic released by weathering of arsenian pyrite is effectively attenuated by adsorption on goethite or coprecipitation with jarosite, depending upon the buffering capacity of the pyrite-bearing rock (Savage and others, 2000). Although jarosite would be expected to dissolve in water having the composition of the developing pit lake, iron oxyhydroxide species (ferrihydrite and goethite) would be stable, and strong partitioning of arsenic onto suspended particles or bottom sediments containing these iron phases would be expected. Arsenic release to the lake would not be expected until stratification develops, producing a reducing, non-circulating hypolimnion in which the iron phases would be destroyed by dissolution. The fact that arsenic concentrations increased rapidly before the pit lake was deep enough to stratify shows that arsenic may not be attenuated in the ways that the earlier Clio mine area study indicated, and suggested that our understanding of release and transport of arsenic in this environment is incomplete. Therefore, in 1997 we decided to study the chemical evolution of the Harvard pit lake as part of a project on environmental impacts of gold mining in the Sierra Nevada, and in early 1998 we developed a cooperative study with several of the investigators in the Stanford University Department of Geological and Environmental Sciences who had done the Clio study. The U.S. Geological Survey portion of the project has been funded by the Mineral Resources Program. It is anticipated that a better understanding of the release and transport of arsenic into the Harvard pit lake and its accumulation there will contribute to more accurate predictions of arsenic release from weathering of sulfide-bearing rocks exposed by mining or other activities or events, and to better forecasts of pit lake evolution in this and similar environments, leading to more effective monitoring and mitigation strategies. An accurate predictive model is needed for the Harvard pit lake to forecast trends in metal concentrations, particularly arsenic, and also concentrations of major cations and anions. As the lake approaches pre-mining groundwater levels the lake water could move down the hydrologic gradient to the southeast into domestic wells, and could also affect the surface water of Woods Creek (see Figures 1-3). This report presents data for water samples collected from March, 1998 through September, 1999. Selected preliminary data for the pit lake for the 1998 calendar year have been reported (Savage and others, 2000).

California↗
USGS2004

Important features of Sustainable Aggregate Resource Management

Every society, whether developed, developing or in a phase of renewal following governmental change, requires stable, adequate and secure supplies of natural resources. In the latter case, there could be significant need for construction materials for rebuilding infrastructure, industrial capacity, and housing. It is essential that these large-volume materials be provided in a rational manner that maximizes their societal contribution and minimizes environmental impacts. We describe an approach to resource management based on the principles of sustainable developed. Sustainable Aggregate Resource Management offers a way of addressing the conflicting needs and interests of environmental, economic, and social systems. Sustainability is an ethics based concept that utilizes science and democratic processes to reach acceptable agreements and tradeoffs among interests, while acknowledging the fundamental importance of the environment and social goods. We discuss the features of sustainable aggregate resource management.

Geologija↗
USGS2024

2024 Crustal Deformation Modeling Workshop report

The 2024 Crustal Deformation Modeling Workshop was held June 10–14 at the Colorado School of Mines. The workshop included two days of tutorials on using PyLith for crustal deformation modeling, followed by three days of science talks and discussions. The workshop focused on four primary themes: ● Constraining long-term fault slip rates and their uncertainties using geodetic and geologic data; ● Earthquake cycle modeling with a focus on constraining models using seismic and geodetic data; ● Interaction of fluids and faulting; and ● Separating contributions of surface loading and tectonic loading in crustal deformation. The complete agenda is available on the CIG website.

Conference Paper↗
USGS1997

Mantle fluids in the San Andreas fault system, California

Fluids associated with the San Andreas and companion faults n central and south-central California have high 3He/4He ratios. The lack of correlation between helium isotopes and fluid chemistry or local geology requires that fluids enter the fault system from the mantle. Mantle fluids passing through the ductile lower crust must enter the brittle fault zone at or near lithostatic pressures; estimates of fluid flux based on helium isotopes suggest that they may thus contribute directly to fault-weakening high-fluid pressures at seismogenic depths.

Science↗
USGS2022

Cohort strength and body size in co-occurring salmonids in a small stream network: Variation in space and time

Trout and salmon commonly coexist in stream networks. Exploring similarities and differences among species can help explain coexistence and invasive ability. Here, we describe spatial distribution, cohort strengths and size-at-age of three co-occurring species in a small stream network. Spatial distributions varied dramatically among species; native brook trout occupied all stream reaches, naturalized brown trout were found in the mainstem and lower portions of tributaries and fry-stocked Atlantic salmon were limited to the mainstem. Size-at-age also differed among species, Atlantic salmon were consistently the smallest, brook trout were intermediate in size and brown trout were the largest. Despite size differences, mean lengths of brook trout and brown trout were highly correlated among years. Cohort strengths varied considerably across years but were also highly correlated for the two trout species, suggesting strong environmental control on cohort strength and a reduced role for species interactions. At low densities, we observed strong negative effects of density on body sizes and weaker effects otherwise. Overall, these results suggest differences in spatial distribution combined with similarities in response to environmental variation contribute to species coexistence in this small steam network.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2010

Proceedings of the 25th Himalaya-Karakoram-Tibet Workshop

For a quarter of a century the Himalayan-Karakoram-Tibet (HKT) Workshop has provided scientists studying the India-Asia collision system a wonderful opportunity for workshop-style discussion with colleagues working in this region. In 2010, HKT returns to North America for the first time since 1996. The 25th international workshop is held from June 7 to10 at San Francisco State University, California. The international community was invited to contribute scientific papers to the workshop, on all aspects of geoscience research in the geographic area of the Tibetan Plateau and its bounding ranges and basins, from basic mapping to geochemical and isotopic analyses to large-scale geophysical imaging experiments. In recognition of the involvement of U.S. Geological Survey (USGS) scientists in a wide range of these activities, the USGS agreed to publish the extended abstracts of the numerous components of HKT-25 as an online Open-File Report, thereby ensuring the wide availability and distribution of these abstracts, particularly in the HKT countries from which many active workers are precluded by cost from attending international meetings. In addition to the workshop characterized by contributed presentations, participants were invited to attend a pre-meeting field trip from the Coast Ranges to the Sierra Nevada, to allow the international group to consider how the tectonic elements of the Pacific margin compare to those of the Himalayan belt. Following the workshop, the National Science Foundation (NSF) sponsored a workshop on the 'Future directions for NSF-sponsored geoscience research in the Himalaya/Tibet' intended to provide NSF Program Directors with a clear statement and vision of community goals for the future, including the scientific progress we can expect if NSF continues its support of projects in this geographic region, and to identify which key geoscience problems and processes are best addressed in the Himalaya and Tibet, what key datasets are needed, and how NSF can best support the evolving need for interdisciplinary investigations. This workshop also has clear societal relevance. Recent earthquakes have brought international attention to active tectonics and earthquake hazards in the HKT region. Prominent examples include the Mw 7.8 Kokoxili (Qinghai, China) earthquake of 2001, the Mw 7.6 Kashmir (Pakistan) earthquake of 2005, the Mw 7.9 Wenchuan (Sichuan, China) earthquake of 2008, and this year the Mw 6.9 Yushu (Qinghai, China) earthquake. Geological and geophysical field work conducted both before these earthquakes, as well as in response to them, has helped to define the active faults and regional tectonics in the HKT region. The research presented at this workshop provides the framework necessary for improved seismic hazard assessments in this region. The organizers gratefully acknowledge the support of NSF's Continental Dynamics Program and its Office of International Science and Engineering, through award EAR-0965796. We thank San Francisco State University's Sheldon Axler, Dean of the College of Science and Engineering, and Toby Garfield, Director of the Romberg Tiburon Center, for use of their conference facilities; and the Department of Geosciences, particularly Deb Shulman and Miriam Knof, for administrative support. The California Academy of Sciences generously hosted a reception for visiting delegates, and Brad Ritts (Chevron Exploration Technology Company), Todd Greene (California State University, Chico) and John Shervais (Utah State University) together co-led the pre-conference field trip. Technical editing of this volume was led by Roxanne Renedo (U.S. Geological Survey) with assistance from Margaret Milia (Stanford University). We are grateful to the U.S. Geological Survey (USGS) Earthquake Hazards Program and the USGS Menlo Park (California) Publishing Service Center for making this online report possible.

Open-File Report↗
USGS2019

Streamflow gains and losses in New Fork and Green Rivers, upstream from Fontenelle Reservoir, Wyoming, October 2015

The Wyoming Landscape Conservation Initiative is a program created to implement a long-term, science-based program of assessing natural resources while facilitating responsible energy and other development and does studies in much of southwestern Wyoming, including all or parts of Lincoln, Sublette, Fremont, Sweetwater, and Carbon Counties. A synoptic study was completed by the U.S. Geological Survey as part of ongoing contributions to the Wyoming Landscape Conservation Initiative to better understand the streamflow dynamics in the New Fork and Green Rivers in an area with historical, current, and future energy development. Streamflow measurements were collected October 19–22, 2015, at 19 sites on the New Fork and Green Rivers in Wyoming to determine changes in streamflow and, where applicable, describe the inflow and outflow of groundwater. Streamflow in the New Fork River generally increased from 50 cubic feet per second (ft 3 /s) at the most upstream site near Pinedale, Wyoming, to 350 ft 3 /s at the mouth of the river. Streamflow in the Green River generally increased downstream from 250 ft 3 /s at the most upstream site at Warren Bridge to around 800 ft 3 /s at the most downstream site near La Barge, Wyo., upstream from Fontenelle Reservoir. Estimated streamflow gains and losses were calculated for five reaches on the New Fork River. Four of the five reaches on the New Fork River had a change greater than the associated measurement error and were gaining reaches; the reach with the largest gain was the most upstream reach. One reach, the most downstream reach, had a calculated change in streamflow less than the associated measurement error. Estimated streamflow gains and losses were calculated for four reaches on the Green River. One reach was determined to be a gaining reach, one was a losing reach, and two reaches had changes less than the associated measurement error. Comparing the annual streamflow hydrographs for three long-term streamgages likely showed the effects of applying irrigation water to the upstream areas of land draining to the Green and New Fork Rivers. Streamflows in the New Fork River near Big Piney and the Green River near La Barge, Wyo., are sustained later in the season compared to the upstream site of Green River at Warren Bridge, which has few diversions and minimal irrigation.

Wyoming↗
USGS2017

Earth Stewardship: An initiative by the Ecological Society of America to foster engagement to sustain Planet Earth

The Ecological Society of America (ESA) has responded to the growing commitment among ecologists to make their science relevant to society through a series of concerted efforts, including the Sustainable Biosphere Initiative (1991), scientific assessment of ecosystem management (1996), ESA’s vision for the future (2003), Rapid Response Teams that respond to environmental crises (2005), and the Earth Stewardship Initiative (2009). During the past 25 years, ESA launched five new journals, largely reflecting the expansion of scholarship linking ecology with broader societal issues. The goal of the Earth Stewardship Initiative is to raise awareness and to explore ways for ecologists and other scientists to contribute more effectively to the sustainability of our planet. This has occurred through four approaches: (1) articulation of the stewardship concept in ESA publications and Website, (2) selection of meeting themes and symposia, (3) engagement of ESA sections in implementing the initiative, and (4) outreach beyond ecology through collaborations and demonstration projects. Collaborations include societies and groups of Earth and social scientists, practitioners and policy makers, religious and business leaders, federal agencies, and artists and writers. The Earth Stewardship Initiative is a work in progress, so next steps likely include continued nurturing of these emerging collaborations, advancing the development of sustainability and stewardship theory, improving communication of stewardship science, and identifying opportunities for scientists and civil society to take actions that move the Earth toward a more sustainable trajectory.

Book chapter↗
USGS2012

A science plan for a comprehensive assessment of water supply in the region underlain by fractured rock in Maryland

The fractured rock region of Maryland, which includes land areas north and west of the Interstate 95 corridor, is the source of water supply for approximately 4.4 million Marylanders, or approximately 76 percent of the State's population. Whereas hundreds of thousands of residents rely on wells (both domestic and community), millions rely on surface-water sources. In this region, land use, geology, topography, water withdrawals, impoundments, and other factors affect water-flow characteristics. The unconfined groundwater systems are closely interconnected with rivers and streams, and are affected by seasonal and climatic variations. During droughts, groundwater levels drop, thereby decreasing well yields, and in some cases, wells have gone dry. Low ground-water levels contribute to reduced streamflows, which in turn, can lead to reduced habitat for aquatic life. Increased demand, over-allocation, population growth, and climate change can affect the future sustainability of water supplies in the region of Maryland underlain by fractured rock. In response to recommendations of the 2008 Advisory Committee on the Management and Protection of the State's Water Resources report, the Maryland Department of the Environment's Water Supply Program, the Maryland Geological Survey, the Maryland Department of Natural Resources, Monitoring and Non-Tidal Assessment (MANTA) Division, and the U.S. Geological Survey have developed a science plan for a comprehensive assessment that will provide new scientific information, new data analysis, and new tools for the State to better manage water resources in the fractured rock region of Maryland. The science plan lays out five goals for the comprehensive assessment: (1) develop tools for the improved management and investigation of groundwater and surface-water resources; (2) characterize factors affecting reliable yields of individual groundwater and surface-water supplies; (3) investigate impacts on nearby water withdrawal users caused by groundwater and surface-water withdrawals; (4) assess the role of streamflow and water withdrawals on the ecological integrity of streams; and (5) improve understanding of the distribution of water-quality conditions in fractured rock aquifers. To accomplish these goals, accurate data collection, review, and analysis are needed, including the study of "Research Watersheds" that can provide detailed information about the potential effects that climate change and water withdrawals may have on groundwater, streamflow, and aquatic life. The assessment planning started in 2009 and is being conducted with close interagency coordination. A Fractured Rock Aquifer Information System is currently (2012) undergoing initial development. Other major tasks that will be performed include the development of work plans for each science goal, the estimation of daily streamflow at ungaged streams, and the design and implementation of Research Watersheds. Finally, scenarios will be modeled to evaluate current water allocation permitting methodologies, investigate effects on nearby water withdrawal users caused by groundwater and surface-water withdrawals, and assess the potential impacts of climate change on water resources. Desktop and Web-based tools will be developed in order to meet the diverse research needs of the assessment. These tools, including the Fractured Rock Aquifer Information System will be continuously improved during the assessment to store relevant groundwater and surface-water data in spatially referenced databases, estimate streamflows, locate higher-yielding wells, estimate the impacts of withdrawals on nearby users, and assess the cumulative impacts of withdrawals on the aquatic resource. Tools will be developed to serve the needs of many audiences, including water resource managers, water suppliers, planners, policymakers, and other scientific investigators.

Maryl↗
USGS2010

U.S. Geological Survey Rewarding Environment Culture Study, 2002

In its 2001 review of the U.S. Geological Survey (USGS), the National Research Council (NRC, p. 126) cautioned that ?high-quality personnel are essential for developing high-quality science information? and urged the USGS to ?devote substantial efforts to recruiting and retaining excellent staff.? Recognizing the importance of the NRC recommendation, the USGS has committed time and resources to create a rewarding work environment with the goal of achieving the following valued outcomes: ? USGS science vitality ? Customer satisfaction with USGS products and services ? Employee perceptions of the USGS as a rewarding place to work ? Heightened employee morale and commitment ? The ability to recruit and retain employees with critical skills To determine whether this investment of time and resources was proving to be successful, the USGS Human Resources Office conducted a Rewarding Environment Culture Study to answer the following four questions. ? Question 1: Does a rewarding work environment lead to the valued outcomes (identified above) that the USGS is seeking? ? Question 2: Which management, supervisory, and leadership behaviors contribute most to creating a rewarding work environment and to achieving the valued outcomes that the USGS is seeking? ? Question 3: Do USGS employees perceive that the USGS is a rewarding place to work? ? Question 4: What actions can and should be taken to enhance the USGS work environment? To begin the study, a conceptual model of a rewarding USGS environment was developed to test assumptions about a rewarding work environment. The Rewarding Environment model identifies the key components that are thought to contribute to a rewarding work environment and the valued outcomes that are thought to result from having a rewarding work environment. The 2002 Organizational Assessment Survey (OAS) was used as the primary data source for the study because it provided the most readily available data. Additional survey data were included as they became available The dividends of creating a rewarding work environment can be great. As the results of the USGS Rewarding Environment Culture Study of 2002 indicate, creating a rewarding work environment is an investment that can have an important impact on the outcomes that the USGS values?the vitality of our science, the satisfaction of our customers, and the morale, commitment, and performance of our employees.

Open-File Report↗
USGS2003

Natural and anthropogenic factors affecting the structure of the benthic macroinvertebrate community in an effluent-dominated reach of the Santa Cruz River, AZ

This study provides an assessment of the ecological conditions of a 46-km effluent-dominated stream section of the Santa Cruz River in the vicinity of the International Waste Water Treatment Plant, Nogales, AZ. We associated changes in the structure of the macroinvertebrate community to natural and anthropogenic chemical and physical variables using multivariate analysis. The analysis shows that biological criteria for effluent-dominated streams can be established using macroinvertebrate community attributes only with an understanding of the contribution of three classes of variables on the community structure: (1) low flow hydrological discharge as affected by groundwater withdrawals, treatment plant discharge, and subsurface geomorphology; (2) chemical composition of the treatment plant discharge and natural dilution; and (3) naturally produced floods resulting from seasonality of precipitation. ?? 2003 Elsevier Science Ltd. All rights reserved.

Ecological Indicators↗