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At least 667 records · Page 37Linked to original sources
USGS2020

Regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, assessed statistical relations between hydraulic properties of streams at approximate bankfull conditions for different ecological regions (ecoregions) in Texas. Data from more than 103,000 records of measured discharge and ancillary hydraulic properties were assembled from summaries of discharge measurements for 424 U.S. Geological Survey streamgages in Texas. The data were subsequently subsetted at each streamgage for a streamgage-specific discharge interval centered on the estimated median annual peak discharge (0.5 annual exceedance probability) obtained from previously published regional regression equations in Texas in conjunction with the streamgage-specific sample median annual peak discharge for the period of record for each streamgage. Discharge measurements at gaged locations representing bankfull conditions (approximated from a discharge interval centered on the estimated median annual peak discharge at a given site) and associated watershed properties were subjected to rigorous statistical analysis. For most discharge measurements (where discharge is symbolically represented as Q ), the following hydraulic properties are available: cross-section area ( A ), water-surface top width ( B ), and reported mean velocity ( V ). Statewide summary statistics were computed by using these four hydraulic properties ( Q , A , B , and V ) and the following five watershed properties: (1) watershed area (contributing drainage area), (2) a multiple of main-channel slope (1,000 times main-channel slope), (3) mean annual precipitation, (4) drainage density, and (5) sinuosity ratio. From the initial set of 424 streamgages, summary statistics were computed for 372 selected streamgages in Texas and constitute the subsetted measurements dataset described in this report. Eight of the 10 ecoregions in Texas are represented in the statewide summary statistics. The resulting statistical relations, expressed as regression equations, can be used to estimate cross-section area, water-surface top width, discharge, and mean velocity of streams in different Texas ecoregions, at approximate bankfull conditions. In the regression equations, watershed properties were the independent variables for applicable watersheds, and predictions from the equations might be useful for estimating the four hydraulic properties at ungaged or unmonitored locations from selected characteristics measured at both the ungaged locations and gaged locations. Four regression equations to estimate the four hydraulic properties were identified as the preferred equations from this study. The four preferred equations use watershed area, mean annual precipitation, and aggregated ecoregion (treated as a categorical variable) to estimate the hydraulic properties, and justification is provided for this preference. For the four equations, the proportions of variance explained by the regression equations as measured by Nash-Sutcliffe efficiency are about 71 percent for cross-section area, 36 percent for top width, 76 percent for discharge, and 25 percent for mean velocity. Residual standard error (RSEs) of the regression equations are 0.252 log10 square feet for cross-section area, 0.319 log10 feet for top width, 0.247 log10 cubic feet per second for discharge, and 0.190 log10 feet per second for mean velocity, and the corresponding standard deviations of response are 0.465 log10 square feet, 0.397 log10 feet, 0.507 log10 cubic feet per second, and 0.220 log10 feet per second, respectively. The residual standard errors are less than the standard deviations as anticipated but show that the uncertainty reduction (percent change) for cross-section area is about −46 percent, about −20 percent for top width, about −51 percent for discharge, and about −14 percent for mean velocity.

Texas↗
USGS2024

Climate-resource scenarios to inform climate change adaptation in Wrangell-St. Elias National Park and Preserve: Summary of 2021 climate change scenario planning

This report illustrates use of scenario planning as a climate change adaptation tool supporting Wrangell-St. Elias National Park and Preserve’s Resource Stewardship Strategy. The primary objective of scenario planning is to help resource managers and scientists make management and planning decisions informed by assessments of critical future uncertainties. This report outlines a process that synthesized future climate projections into three distinct but plausible and relevant climate summaries for the focal area and used them to develop climate-resource scenarios through participatory scenario planning. Initial steps identified the priority resource management topics and the corresponding related climate uncertainties. Next, local climate summaries were used to develop divergent climate futures: those that describe the broadest possible range of plausible conditions while capturing relevant uncertainty. The final phase further developed the climate futures and their resource implications. These participatory scenario planning exercises occurred virtually in fall (August–November) 2021. The climate-resource scenarios informed adaptation strategies in conjunction with the park’s Resource Stewardship Strategy development. The scope and complexity of this effort is unique but elements from the scenarios and resource implications have broad applicability to other large, protected areas in Alaska and Northwest Canada.

Alaska↗
USGS1949

Progress report on the sea lamprey study

SUMMARY: The Peromyscus leucopus on a 17-acre study area were live-trapped, marked, and released over a seven-day period. On the three following nights intensive snap-trapping was done on the central acre of the study plot. The animals caught by snap traps in the central acre represented the population of the central acre and several surrounding acres. By the currently accepted methods of interpreting snap-trap data, the population per acre would be considered to be 23 adults. The live-trap data show that the true population was between six and seven adults per acre. Modern methods of live-trapping are shown to be valid for population studies. Two methods are presented for the conversion of live-trap data into per acre figures. Errors involved in the current use of snap-trap data are discussed and snap-trap methods are shown to be invalid for determining actual population numbers. It should be practical to use a snap-trap quadrant technique to obtain a relative measure or index figure for small mammal populations.

The Fisherman↗
USGS2011

Assessment of surface-water quantity and quality, Eagle River watershed, Colorado, 1947-2007

From the early mining days to the current tourism-based economy, the Eagle River watershed (ERW) in central Colorado has undergone a sequence of land-use changes that has affected the hydrology, habitat, and water quality of the area. In 2000, the USGS, in cooperation with the Colorado River Water Conservation District, Eagle County, Eagle River Water and Sanitation District, Upper Eagle Regional Water Authority, Colorado Department of Transportation, City of Aurora, Town of Eagle, Town of Gypsum, Town of Minturn, Town of Vail, Vail Resorts, City of Colorado Springs, Colorado Springs Utilities, and Denver Water, initiated a retrospective analysis of surface-water quantity and quality in the ERW. Surface-water quantity data and surface-water quality data were obtained from local, State, and Federal agencies to assist in the analysis of surface-water conditions in the ERW 1947-2007. Surface-water-quality data from 293 sites and 12 different source agencies were compiled into 192 unique sites located on streams and rivers in the ERW. Approximately 39 percent of the unique sites had fewer than 5 samples; while 23 percent of the sites had more than 100 samples. Physical properties were the most abundant type of samples collected, with major ions, nutrients, and trace elements also commonly collected. For selected water-quality properties and constituents in the watershed, this report: (1) characterizes available water quantity and water-quality data, (2) identifies spatial and seasonal variability in water quantity and water quality, (3) provides comparisons to Federal and State water-quality standards or recommendations, (4) characterizes temporal changes in water quality, and (5) where possible, identifies potential causes of these changes. This report provides reconnaissance-level statistical summaries and comparisons of water-quality conditions and characteristics using available data within the ERW. The report also includes streamflow statistics such as: mean annual runoff totals, peak-flood-frequency recurrence intervals, and minimum 7-day mean streamflows for selected sites within the watershed. The spatial patterns for concentrations of trace metals (aluminum, cadmium, copper, iron, manganese, and zinc) indicate an increase in dissolved concentrations of these metals near historical mining areas in the Eagle River and several tributaries near Belden. In general, concentrations decrease downstream from mining areas. Concentrations typically are near or below reporting limits in Gore Creek and other tributaries within the watershed. Concentrations for trace elements (arsenic, selenium, and uranium) in the watershed usually are below the reporting limit, and no prevailing spatial patterns were observed in the data. Step-trend analysis and temporal-trend analysis provide evidence that remediation of historical mining areas in the upper Eagle River have led to observed decreases in metals concentrations in many surface-waters. Comparison of pre- and post-remediation concentrations for many metals indicates significant decreases in metals concentrations for cadmium, manganese, and zinc at sites downstream from the Eagle Mine Superfund Site. Some sites show order of magnitude reductions in median concentrations between these two periods. Evaluation of monotonic trends for dissolved metals concentrations show downward trends at numerous sites in, and downstream from, historic mining areas. The spatial pattern of nutrients shows lower concentrations on many tributaries and on the Eagle River upstream from Red Cliff with increases in nutrients downstream of major urban areas. Seasonal variations show that for many nutrient species, concentrations tend to be lowest May-June and highest January-March. The gradual changes in concentrations between seasons may be related to dilution effects from increases and decreases in streamflow. Upward trends in nutrients between the towns of Gypsum and Avon were detected for nitrate, orthophosphate, and total phosphorus. An upward trend in nitrite was detected in Gore Creek. No trends were detected in un-ionized ammonia within the ERW. Exceedances of State water-quality standards (nitrite, nitrate, and un-ionized ammonia) and levels higher than U.S. Environmental Protection Agency recommendations (total phosphorus) occur in several areas within the ERW. The majority of the exceedances are from comparisons to the U.S. Environmental Protection Agency total phosphorus recommendations. A positive correlation was observed between suspended sediment and total phosphorus. An upward trend in total dissolved solids in Gore Creek may be the result of increases in chloride salts. Highly significant trends were detected in sodium, potassium, and chloride with a significant upward trend in magnesium and a weakly significant upward trend in calcium. A quantitative analysis of the relative abundance of calcium, magnesium, sodium, and potassium to the available anions suggests that chloride salts likely are the source for the detected upward trends because chloride is the only commonly occurring anion with a trend in Gore Greek. A potential source for the observed chloride salts may be the chemical anti-icing and deicing products used during winter road maintenance in municipal areas and on Interstate-70. A downward trend in dissolved solids in the Eagle River between Gypsum and Avon may be contributing to the detected trend on the Eagle River at Gypsum. Significant downward trends were detected in specific ions such as calcium, magnesium, sulfate, and silica. Measures of total dissolved solids as well as comparisons to specific ions show that in water-quality samples within the ERW concentrations generally are lower in the headwaters, with increases downstream from Wolcott. Differences in concentrations likely result from increased abundance of salt-bearing geologic units downstream from Avon. Few sites had measured concentrations that exceeded the State standards for chloride.

Scientific Investigations Report↗
USGS2004

Chemical Data for Detailed Studies of Irrigation Drainage in the Salton Sea Area, California, 1995?2001

The primary purpose of this report is to present all chemical data from the Salton Sea area collected by the U.S. Geological Survey between 1995 and 2001. The data were collected primarily for the Department of the Interior's National Irrigation Water Quality Program (NIWQP). The report also contains a brief summary and citation to investigations done for the NIWQP between 1992 and 1995. The NIWQP began studies in the Salton Sea area in 1986 to evaluate effects on the environment from potential toxins, especially selenium, in irrigation-induced drainage. This data report is a companion to several reports published from the earlier studies and to interpretive publications that make use of historical and recent data from this area. Data reported herein are from five collection studies. Water, bottom material, and suspended sediment collected in 1995-96 from the New River, the lower Colorado River, and the All-American Canal were analyzed for elements, semi-volatile (extractable) organic compounds, and organochlorine compounds. Sufficient suspended sediment for chemical analyses was obtained by tangential-flow filtration. A grab sample of surficial bottom sediment collected from near the deepest part of the Salton Sea in 1996 was analyzed for 44 elements and organic and inorganic carbon. High selenium concentration confirmed the effective transfer (sequestration) of selenium into the bottom sediment. Similar grab samples were collected 2 years later (1998) from 11 locations in the Salton Sea and analyzed for elements, as before, and also for nutrients, organochlorine compounds, and polycyclic aromatic hydrocarbons. Nutrients were measured in bottom water, and water-column profiles were obtained for pH, conductance, temperature, and dissolved oxygen. Element and nutrient concentrations were obtained in 1999 from cores at 2 of the above 11 sites, in the north subbasin of the Salton Sea. The most-recent study reported herein was done in 2001 and contains element data on suspended material isolated by continuous-flow centrifugation on samples collected in transects extending out from the Whitewater, the Alamo, and the New Rivers into the Salton Sea. Chemical data on suspended sediment and bottom material from tributory rivers and the Salton Sea itself show that many insoluble constituents, including selenium and DDE, are concentrated in the fine-grained, organic- and carbonate-rich bottom sediment from deep areas near the center of the Salton Sea. Data also show that selenium and arsenic are markedly enriched in seston (plankton, partially-degraded algal detritus, and mineral matter that compose suspended particulates in the lake) collected just below the water surface in the Salton Sea. This result indicates that bio-concentration in primary producers in the water column provides an important pathway whereby high selenium residues accumulate in fish and fish-eating birds at the Salton Sea.

Scientific Investigations Report↗
USGS2013

A compilation of U.S. Geological Survey pesticide concentration data for water and sediment in the Sacramento–San Joaquin Delta region: 1990–2010

Beginning around 2000, abundance indices of four pelagic fishes (delta smelt, striped bass, longfin smelt, and threadfin shad) within the San Francisco Bay and Sacramento–San Joaquin Delta began to decline sharply (Sommer and others, 2007). These declines collectively became known as the pelagic organism decline (POD). No single cause has been linked to this decline, and current theories suggest that combinations of multiple stressors are likely to blame. Contaminants (including current-use pesticides) are one potential stressor being investigated for its role in the POD (Anderson, 2007). Pesticide concentration data collected by the U.S. Geological Survey (USGS) at multiple sites in the delta region over the past two decades are critical to understanding the potential effects of current-use pesticides on species of concern as well as the overall health of the delta ecosystem. In April 2010, a compilation of contaminant data for the delta region was published by the State Water Resources Control Board (Johnson and others, 2010). Pesticide occurrence was the major focus of this report, which concluded that “there was insufficient high quality data available to make conclusions about the potential role of specific contaminants in the POD.” The report cited multiple sources; however, data collected by the USGS were not included in the publication even though these data met all criteria listed for inclusion in the report. What follows is a summary of publicly available USGS data for pesticide concentrations in surface water and sediments within the Sacramento–San Joaquin Delta region from the years 1990 through 2010. Data were retrieved though the USGS National Water Information System (NWIS) database, a publicly available online-data repository (U.S. Geological Survey, 1998), and from published USGS reports (also available online at http://pubs.er.usgs.gov/). The majority of the data were collected in support of two long term USGS monitoring programs—National Water Quality Assessment Program (NAWQA; http://water.usgs.gov/ nawqa/) and National Stream Quality Accounting Network (NASQAN; http://water.usgs.gov/nasqan/)—and through projects associated with the USGS Toxics Substances Hydrology Program (http://toxics.usgs.gov/). In addition, data were collected during multiple research projects that were supported by various federal, state, and local agencies. Although these data have been previously published in some form, it is hoped that by focusing on samples collected within the delta region and presenting these data in a concise format, they will be a valuable resource for scientists, resource managers, and members of the public working to understand the role of pesticides in the POD and their potential effects on the overall health of the delta ecosystem.

California↗
USGS2026

Cruise summary—Samoa Basin abyssal mapping—Box coring leg, Pago Pago, Territory of American Samoa to Pago Pago, American Samoa, April 11– May 1, 2026

Expedition Summary U.S. Geological Survey scientists led a box coring effort to the Samoa Basin to characterize minerals and the surrounding abyssal sediments and fauna. Thirty-eight box cores were deployed between April 13, 2026, and April 28, 2026. Thirty-six box cores recovered sufficient material to determine nodule density, and 35 recovered sufficient material for subcores to be collected. The purpose of this Data Report is to provide a summary of samples collected, initial results that were obtained shipboard, and briefly mention planned future analyses from this expedition.

Data Report↗
USGS2025

Characterizing Meteor Crater impact melts through geochemistry and textural analysis

The U.S. Geological Survey Astrogeology Science Center houses the Meteor Crater sample collection, an assemblage of over 2,500 meters of cuttings from 161 drill holes into Meteor Crater’s rim, flanks, and ejecta blanket. We have utilized this unique collection to study the composition and spatial distribution of impact-generated materials from within the ejecta blanket. Meteor Crater has historically been known to have generated only a relatively small amount of impact melt compared to other terrestrial craters of similar size. A detailed compositional and textural dataset of impact-derived melts from this impact can therefore be a useful asset in improving our understanding of crater formation, and in particular impact melt formation. We have characterized 42 impact-melt particles from Meteor Crater using a scanning electron microscope and an electron microprobe for textural and compositional analysis. We analyzed samples from six drill holes in the ejecta blanket, situated to the northwest, southeast, south, and southwest of the crater (ejecta northeast of the crater is devoid of impact melts). Impact melts were collected from drill cuttings at various depths within the ejecta blanket, ranging from a few centimeters below the surface down to ~6.5 meters. Backscattered electron (BSE) images were acquired for each analyzed impact-melt particle. To characterize the various textures and phases present in each impact melt, we also took many detailed BSE images. Our geochemical analyses include full spectral profiles using energy dispersive X-ray spectrometry and well-calibrated wavelength dispersive spectrometry for a number of phases, including minerals (olivine, pyroxene, and so on), pristine glass, and metallic inclusions. The full dataset is available in ScienceBase as a data release (Gullikson and others, 2024), accessible at https://doi.org/10.5066/P9OGAJ8P . Our goal for this Open-File Report is to provide a summary of this immense dataset, details on data collection, descriptions of the different phases observed within impact-melt particles (both geochemically and texturally), and observable trends.

Arizona↗
USGS2013

Metallogenic belt and mineral deposit maps of northeast Asia

This report contains explanatory material and summary tables for lode mineral deposits and placer districts (Map A, sheet 1) and metallogenic belts of Northeast Asia (Maps B, C, and D on sheets 2, 3, and 4, respectively). The map region includes eastern Siberia, southeastern Russia, Mongolia, northeast China, and Japan. A large group of geologists—members of the joint international project, Major Mineral Deposits, Metallogenesis, and Tectonics of Northeast Asia—prepared the maps, tables, and introductory text. This is a cooperative project with the Russian Academy of Sciences, Mongolian Academy of Sciences, Mongolian National University, Ulaanbaatar, Mongolian Technical University, Mineral Resources Authority of Mongolia, Geological Research Institute, Jilin University, China Geological Survey, Korea Institute of Geoscience and Mineral Resources, Geological Survey of Japan, and U.S. Geological Survey. This report is one of a series of reports on the mineral resources, geodynamics, and metallogenesis of Northeast Asia. Companion studies include (1) a detailed geodynamics map of Northeast Asia (Parfenov and others, 2003); (2) a compilation of major mineral deposit models (Rodionov and Nokleberg, 2000; Rodionov and others, 2000); (3) a series of metallogenic belt maps (Obolenskiy and others, 2004); (4) location map of lode mineral deposits and placer districts of Northeast Asia (Ariunbileg and others, 2003b); (5) descriptions of metallogenic belts (Rodionov and others, 2004); (6) a database on significant metalliferous and selected nonmetalliferous lode deposits and selected placer districts (Ariunbileg and others, 2003a); and (7) a series of summary project publications (Ariunbileg and 74 others, 2003b).

Asia↗
USGS1989

Summary of hydrologic data for the San Gabriel River basin and Edwards Aquifer, Georgetown area, Texas, water year 1988

The Edwards aquifer is the principle source of freshwater for municipal, domestic, and industrial users in the Georgetown area. Other sources of freshwater are the streams draining the San Gabriel River basin and Lake Georgetown. Lake Georgetown, located on the North Fork San Gabriel River west of Georgetown, is a freshwater supply for some municipalities in the area, water in the San Gabriel River basin also supplies a variety of needs east of Georgetown. Because of the importance of the Edwards aquifer and the surface waters in the area, the U.S. Geological Survey, in cooperation with the city of Georgetown, conducted a monitoring program of the Edwards Aquifer and principal streams during water year 1988. The study area centered on Georgetown and encompassed an area of about 150 square miles (fig. 1). The freshwater resources in the Georgetown area have been the subject of three recent reports. Baker and others (1986) described the Edwards aquifer and the relation between recharge and discharge. Krietier and others (1987) provided fracture analysis, geologic mapping, ground-water chemistry, and the relation between rainfall and recharge in the study area. Land and Dorsey (1988) conducted an investigation to reassess the inclusion of the Georgetown Limestone as one of the geologic units comprising the Edwards aquifer. In addition, the Geological Survey publishes streamflow and water-quality data in the Water Resources Data for Texas report on an annual basis. The primary purpose of this report is to present a summary of the hydrologic data collected from the streams draining the San Gabriel River basin and from the Edwards aquifer during the 1988 water year (October 1987–September 1988). A secondary purpose is to add perspective to the 1988 data by including data from the previous 2 years (1986 and 1987) when available. The scope of the report is limited to the Georgetown area (fig. 1) and to data collected by the Geological Survey.

Texas↗
USGS1992

Geologic framework of pre-Cretaceous rocks in the Southern Ute Indian Reservation and adjacent areas, southwestern Colorado and northwestern New Mexico

This report is a discussion and summary of Jurassic and older rocks in the Southern Ute Indian Reservation and adjacent areas, southwestern Colorado and northwestern New Mexico, and is based on analysis of geophysical logs and observations of outcrops. The Reservation, which is located in the northern San Juan Basin, has been the site of deposition of sediments for much of the Phanerozoic. Geologic times represented on the Reservation are the Precambrian, Cambrian, Devonian, Mississippian, Pennsylvanian, Permian, Triassic, Jurassic, Cretaceous, Tertiary, and Quaternary. Rocks of Ordovician and Silurian age have not been reported in this region. Thicknesses of pre-Cretaceous sedimentary rocks range from about 750 feet (229 meters) on the Archuleta arch, east of the Reservation, to more than 8,300 feet (2,530 meters) just northwest of the Reservation. About 5,500 feet (1,676 meters) of pre-Cretaceous sedimentary rocks occur in the central part of the Reservation, near Ignacio. At Ignacio the top of the Jurassic lies at a depth of 7,600 feet (2,316 meters) below the surface, which is composed of Tertiary rocks. As much as 2,500 feet (762 meters) of Tertiary rocks occur in the area. More than 10,000 feet (3,048 meters) of Cretaceous and younger rocks, and 15,600 feet (4,755 meters) of all Phanerozoic sedimentary rocks occur in the vicinity of the Reservation. In the early Paleozoic the area that includes the Southern Ute Reservation was on the stable western shelf of the craton. During this time sediments that compose the following shallow-marine clastic and carbonate rocks were deposited: the Upper Cambrian Ignacio Quartzite (0-150 feet; 0-46 meters), Upper Devonian Elbert Formation (50-200 feet; 15-61 meters), Upper Devonian Ouray Limestone (10-75 feet; 3-23 meters), and Mississippian Leadville Limestone (0-250 feet; 0-76 meters). Mixed carbonate and clastic deposition, which was punctuated by a unique episode of deposition of evaporite sediments, continued through the Pennsylvanian after a significant episode of erosion at the end of the Mississippian. Pennsylvanian rocks on the Reservation are the Molas Formation (20-100 feet; 6-30 meters) and Hermosa Group (400-2,800 feet; 122-853 meters), which consists of the Pinkerton Trail Formation (40-120 feet; 12-36 meters), Paradox Formation and equivalent rocks (200-1,800 feet; 61-549 meters), and Honaker Trail Formation (200-1,300 feet; 61-396 meters). A unit that is transitional between the Pennsylvanian and Permian is the Rico Formation, which is about 200 feet (61 meters) thick across most of the Reservation area. The close of the Paleozoic Era was marked by a great influx of arkosic clastic sediments from uplifted highlands to the north of the Reservation area during the Permian. Near the paleomountain front the Cutler Formation (presently as thick as 8,000 feet; 2,438 meters) formed as a result of deposition of arkosic sediments; however, the original thickness of the Cutler is unknown due to an unconformity at its top. In the area of the Reservation the Cutler has group status and has been divided into several formations: the Halgaito Formation (350-800 feet; 107-244 meters), Cedar Mesa Sandstone and equivalent rocks (150-350 feet; 46-107 meters), Organ Rock Formation (500-900 feet; 152-274 meters), and De Chelly Sandstone (0-100 feet; 0-30 meters). The sediments of these formations were deposited in a variety of environments, including eolian, mud-flat, and fluvial systems. Following an episode of erosion in the Early and Middle(?) Triassic, deposition in the area of the Southern Ute Reservation continued during the Mesozoic. Sediments of the Upper Triassic Dolores and correlative Chinle Formations were deposited in fluvial, lacustrine, and minor eolian environments. On the Reservation the Dolores is 500-1,200 feet (152-366 meters) thick. Lower Jurassic eolian and fluvial deposits may have been present in much of the Reservation area but have been removed

Professional Paper↗
USGS1998

The last interglaciation at Owens Lake, California; Core OL-92

Owens Lake, located at the eastern base of the central Sierra Nevada (Fig. 1), was the terminus of the Owens River prior to the lake's complete desiccation shortly after 1913 due to river diversion by the City of Los Angeles. During earlier wetter cycles, the lake overflowed to fill a series of downstream basins including China Lake Basin, Searles Valley, Panamint Valley, and ultimately, Death Valley (Smith and Street-Perrott, 1983). In 1992 the U.S. Geological Survey drilled a 323-m-deep core (OL-92) into Owens Lake sediments near the depocenter of the basin to obtain a continuous record of silty-clay sediment spanning the last 800,000 yrs. A multi-parameter reconnaissance study of the entire core (ca 7000-yr resolution), was reported in a 13-chapter summary volume (Smith and Bischoff, 1997). A document containing the numerical and other detailed forms of raw data collected by that volume's authors was prepared earlier (Smith and Bischoff, 1993). The reconnaissance study provided an approximate time-depth model for the entire core, based on radiocarbon dates from the top 31m, the Bishop Ash (759,000 yrs) at 304 m, ten within-Brunhes paleomagnetic excursions, and a compaction-corrected mass-accumulation rate of 51.4 g/cm/l000yr (Bischoff et al., 1997a). Application of this model to observed sediment parameters indicates that Owens Lake was saline, alkaline, and biologically productive at times of decreased water-flow, and was generally hydrologically flushed and relatively unproductive during times of increased water-flow. Grain size, abundance of CaCO 3 , organic carbon, clay mineralogy, cation-exchange capacity of the clay fraction, fossil pollen, fish, ostracodes, and diatoms (see summary by Smith et al., 1997) all show cyclic variation down the core. CaCO 3 abundance, in particular, strongly reflects an approximately 100 ka dominant cycle, characteristic of global ice-volume indicated by the MIS δ 18 O record. Four of the last five marine isotope terminations are clearly shown in the OL-92 record.

California↗
USGS1982

U.S. Geological Survey activities, fiscal year 1981

This U.S. Geological Survey Activities report for fiscal year 1981 presents a summary of the work performed between October 1, 1980 and September 30, 1981. The main sections of this report are: (1) The Year in Review; a brief overview of the significant events of the Geological Survey during fiscal year 1980; (2) Perspectives; essays focusing on specific events (rather than scientific topics) and programs involving multi-Division participation; (3) Missions, Organization, and Budget; a description of the Geological Survey 's major duties and assignments and of the organizational structure that supports its missions; and (4) Division Chapters; a description of the significant accomplishments (rather than a comprehensive program by program discussion) of each of the eight operating Divisions and Offices. Also included are supplementary information regarding key personnel, cooperators, and selected summary budgetary tables. (USGS)

Circular↗
USGS1989

Dissolved-solids data for the James River salinity model, North Dakota and South Dakota

Operation of the Garrison Diversion Unit in North Dakota will divert water from the Missouri River into the James River basin and thereby augment flows in the James River sufficiently to permit expanded irrigation and to provide new water supplies for municipal and industrial use. Salinity of water in the James River currently is marginal for irrigation use f and expanded irrigation may increase river-water salinity beyond acceptable limits. Monthly mean dissolved solids are required by the U.S. Bureau of Reclamation salinity model to predict the effects of different management practices on salinity in the James River. The purpose of this report is to provide a summary of available dissolved-solids data and to discuss methodology to calculate monthly mean dissolved solids. Equations were developed by relating dissolved solids to specific conductance and also by relating specific conductance to streamflow for 15 gaging stations in the James River basin. Dissolved-solids data for supplemental surface-water and ground-water sources to the James River also are summarized.

North Dakota, South Dakota↗
USGS2017

Report from the Workshop on Coregonine Restoration Science

Summary Great Lakes fishery managers have the opportunity and have expressed interest in reestablishing a native forage base in the Great Lakes consisting of various forms and species within the genus Coregonus . This report summarizes the proceedings of a workshop focused on a subset of the genus, and the term “coregonines” is used to refer to several species of deepwater ciscoes (also known as “chubs”) and the one more pelagic-oriented cisco species ( Coregonus artedi , also known as “lake herring”). As the principal conservation agency for the United States Government, the Department of Interior has unique and significant authorities and capacities to support a coregonine reestablishment program in the Great Lakes. To identify and discuss key uncertainties associated with such a program and develop a coordinated approach, the U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service (FWS), the principal Department of the Interior bureaus to address Great Lakes fishery issues, held the first of a series of workshops on coregonine science in Ann Arbor, Michigan, on October 11–13, 2016. Workshop objectives were to identify (1) perceived key uncertainties associated with coregonine restoration in the Great Lakes and (2) DOI capacities for addressing these key uncertainties.

Open-File Report↗
USGS2022

Effects of climate change on fish and wildlife species in the United States

About this volume This U.S. Geological Survey Open-File Report provides brief syntheses of the direct and indirect effects of climate change to priority species and ecosystems in the United States. Each chapter focuses on changes in climate and related e ffects to the life cycle , interspec i fic interactions, and habitats of a fish or wildlife species of conservation concern. These reports are independent species-specific summaries of relevant literature, current and historic climate conditions, and future climate projections.

Open-File Report↗
USGS1978

Workshop summary

Explore the source record for details and available documents.

FWS/OBS↗