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At least 343 records · Page 19Linked to original sources
USGS1978

Appraisal of uncontrolled flowing artesian wells in Florida

An estimated 15,000 uncontrolled flowing wells, many discharging water of poor quality are wastefully discharging about 790 million gallons per day by surface and internal flow. Internal flow in principal problem areas have been identified in Brevard, Charlotte, Clay, De Soto, Duval, Flagler, Glades, Hendry, Hillsborough, Lee, Manatee, Martin, Nassau, and Sarasota Counties. In many areas, uncontrolled discharge over the years has caused a decline in the potentiometric surface locally and regionally, and a deterioration of the potable water aquifers. Programs for control of flowing wells are being carried on by State, county, municipal, or Federal agencies in 21 countries. (Woodard-USGS)

Water-Resources Investigations Report↗
USGS2014

Trophic state in Voyageurs National Park lakes before and after implementation of a revised water-level management plan

We compiled Secchi depth, total phosphorus, and chlorophyll a (Chla) data from Voyageurs National Park lakes and compared datasets before and after a new water-level management plan was implemented in January 2000. Average Secchi depth transparency improved (from 1.9 to 2.1 m, p = 0.020) between 1977-1999 and 2000-2011 in Kabetogama Lake for August samples only and remained unchanged in Rainy, Namakan, and Sand Point Lakes, and Black Bay in Rainy Lake. Average open-water season Chla concentration decreased in Black Bay (from an average of 13 to 6.0 μg/l, p = 0.001) and Kabetogama Lake (from 9.9 to 6.2 μg/l, p = 0.006) between 1977-1999 and 2000-2011. Trophic state index decreased significantly in Black Bay from 59 to 51 (p = 0.006) and in Kabetogama Lake from 57 to 50 (p = 0.006) between 1977-1999 and 2000-2011. Trophic state indices based on Chla indicated that after 2000, Sand Point, Namakan, and Rainy Lakes remained oligotrophic, whereas eutrophication has decreased in Kabetogama Lake and Black Bay. Although nutrient inputs from inflows and internal sources are still sufficient to produce annual cyanobacterial blooms and may inhibit designated water uses, trophic state has decreased for Kabetogama Lake and Black Bay and there has been no decline in lake ecosystem health since the implementation of the revised water-level management plan.

Minnesota↗
USGS2013

Internal nutrient sources and nutrient distributions in Alviso Pond A3W, California

Within the Alviso Salt Pond complex, California, currently undergoing avian-habitat restoration, pore-water profilers (U.S. Patent 8,051,727 B1) were deployed in triplicate at two contrasting sites in Pond A3W (“Inlet”, near the inflow, and “Deep”, near the middle of the pond; figs. 1 and 2; table 1, note that tables in this report are provided online only as a .xlsx workbook at http://pubs.usgs.gov/of/2013/1128/). Deployments were conducted in 2010 and 2012 during the summer algal-growth season. Specifically, three deployments, each about 7 weeks apart, were undertaken each summer. This study provides the first measurements of the diffusive flux of nutrients across the interface between the pond bed and water column (that is, benthic nutrient flux). These nutrient fluxes are crucial to pond restoration efforts because they typically represent a major (if not the greatest) source of nutrients to the water column in both ponds and other lentic systems. For soluble reactive phosphorus (SRP, the most biologically available form in solution), benthic flux was positive both years (that is, out of the sediment into the water column; table 2), with the exception of the August 2010 deployment, which exhibited nearly negligible but negative flux. Overall, the average SRP flux was significantly greater at Deep (23.9 ± 8.6 micromoles per square meter per hour (µmol-m -2 -h -1 ); all errors shown reflect the 95-percent confidence interval) than Inlet (12.6 ± 4.9 µmol-m -2 -h -1 ). There was much greater temporal variability in SRP flux in the pond than reported for the lower estuary (Topping and others, 2001). For dissolved ammonia, benthic flux was consistently positive on all six sampling trips, and similar to SRP, the fluxes at Deep (258 ± 49 µmol-m -2 -h -1 ) were consistently greater than those at Inlet (28 ± 11 µmol-m -2 -h -1 ). Dissolved ammonia fluxes reported for South San Francisco Bay by Topping and others (2001) fall in between these values. Once again, greater variability for benthic fluxes determined in the pond was observed relative to adjacent South San Francisco Bay. With the near absence of any measurable concentration gradient, dissolved-nitrate fluxes were consistently negligible in the pond. Silica fluxes are often used to represent sediment diagenetic processes that biogeochemically cycle silica (an important algal macronutrient) between biogenic and inorganic phases (Fanning and Pilson, 1974; Emerson and others, 1984). For South San Francisco Bay, those values are consistently positive from core-incubation experiments. In Pond A3W, dissolved-silica fluxes averaged 49 ± 25 µmol-m -2 -h -1 at Inlet and were much higher at Deep (482 ± 370 µmol-m -2 -h -1 ), similar to the spatially variability observed for SRP and dissolved ammonia. An elevated silica flux can stimulate diatom production and subsequent eutrophication effects. Variability in these silica fluxes is consistent with season patterns in pond primary productivity. On the basis of comparisons of dissolved-oxygen flux measurements by profilers and core incubations, it appears that diffusive flux estimates for the sediment in this pond, as one might expected in such benthically productive environments, result in a significant underestimation of true sediment oxygen demand. Therefore, a core incubation experiment was conducted to better quantify the demand. To complement these benthic-flux studies, a diurnal study of nutrient advective flux into and out of the pond was measured during neap and spring tides to provide comparative estimates for allochthonous solute transport (Garret, 2012). Using the two different tides as the probable upper and lower boundaries, we can estimate a range of probable values throughout the year. After converting this advective flux into kg/yr, we can compare it directly to benthic flux estimates for the pond extrapolated over the 2.27 square kilometer (km 2 ) pond surface. Benthic flux of nitrogen species, averaged over all sites and dates, was about 80,000 kilograms per year (kg/yr), well above the adjective flux range of -50 to 1,500 kg/yr. By contrast, the average benthic flux of orthophosphate was about 12,000 kg/yr, well below the advective flux range of 21,500 to 30,000 kg/yr. Initial benthic flux estimates were also made for trace metals, including copper, nickel, iron, and manganese. These analyses indicated that the two sites, Inlet and Deep, have different pore-water profiles, with Inlet exhibiting much higher benthic flux estimates for nickel, iron, and manganese. These initial benthic-flux values reported for macronutrients are particularly impressive in magnitude when one considers that diffusive flux of dissolved solutes based on pore-water profiles provides a conservative determination that may be enhanced by other biogeochemical processes. These enhancement processes (Boudreau and Jorgensen, 2001) include bioturbation, bioirrigation, wind resuspension, and potential groundwater inflows, some of which are captured in core-incubation experiments (Kuwabara and others, 2009). Hence, the values reported herein represent lower bounds to indicate the potential importance of such internal solute sources. The elevated diffusive fluxes for nutrients in the pond relative to the adjacent estuary indicate that vertical nutrient transport between the pond bed and water column is consistently an important (and at times the most important) source of nutrients that stimulate phytoplankton growth in the water column. One might therefore reasonably hypothesize that this benthic transport of biologically reactive solutes (both nutrients and toxicants) represents the most important step at the base of the food web for trophic transfer.

California↗
USGS2010

Geologic nozzles

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1–10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the gyeser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. The transport capacity in the rapids can be so great that the river contours the channel to a characteristic shape. This shape can be used to interpret the flood history of the Colorado River over the past 10³–10 5 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

Arizona, Washington, Wyoming↗
USGS2021

Long-term epilimnetic temperature trends in Lake Mendota and Trout Lake, Wisconsin

Warming of lake surface waters has become a concern to limnologists and water managers because a ir temperatures, which directly affect near - surface water temperatures, are projected to increase in Wisconsin (WICCI 2011) as well as globally (IPCC 2018). This projected increase is in addition to the changes in air temperatures that have already occurred in recent decade s (WICCI 2011, NOAA 2017) . The deleterious effects of increased temperatures in lake surface waters have been extensively reviewed ( e.g., Blenckner 2005, Keller 2007, Adrian et al. 2009, George 2010 ) . Briefly , t he exceedance of thermal preferences or tolerances of aquatic biota can cause altered food webs and loss of biodiversity in lakes ( De Stasio et al. 199 6 , Chu et al. 2005, Graham and Harrod 2009, Woodward et al. 2010, Comte et al. 2013 ) . W armer surface water temperature s can result in stronger and longer thermal stratification in deep lakes ( Robertson and Ragotzkie 1990, Hondzo and Stefan 1993, Livingstone 2003, Butcher et al. 2015 ) . This process in turn can cause the duration and extent of hypolimnetic anoxia to increase, thus reducing hypolimnetic refugia needed for cold - and cool - water fish ( De Stasio et al. 1996 , Magnuson et al. 1997, Jeppesen et al. 2012 , Missaghi et al. 2017) . Longer duration of hypolimnetic anoxia can enhance eutrophic ation because of more internal loading of phosphorus from bottom sediments ( Blenckner et al. 2002, North et al. 2014 ) . Of parti cular concern, w armer water temperatures favor the growth of toxic cyanobacteria in eutrophic systems ( Paerl and Huisman 2008, Wagner and Adrian 2009, Kosten et al. 2012 ) . Another effect of warmer lake surface temperature s is increased evaporation that can result in lower water levels ( Spence et al. 2013, Gronewold and Stow 2014 ) .

Wisconsin↗
USGS2021

Statistical methods for simulating structural stormwater runoff best management practices (BMPs) with the Stochastic Empirical Loading and Dilution Model (SELDM)

This report documents statistics for simulating structural stormwater runoff best management practices (BMPs) with the Stochastic Empirical Loading and Dilution Model (SELDM). The U.S. Geological Survey developed SELDM and the statistics documented in this report in cooperation with the Federal Highway Administration to indicate the risk for stormwater flows, concentrations, and loads to exceed user-selected water-quality goals and the potential effectiveness of mitigation measures to reduce such risks. In SELDM, three treatment variables—hydrograph extension, volume reduction, and water-quality treatment—are simulated by using the trapezoidal distribution and the rank correlation with the associated runoff variables. This report describes methods for calculating the trapezoidal distribution statistics and rank correlation coefficients for these treatment variables and methods for estimating the minimum irreducible concentration (MIC), which is the lowest expected effluent concentration from a BMP site or a category of BMPs. These statistics are different from the statistics commonly used to characterize or compare BMPs; they are designed to provide a stochastic transfer function to approximate the quantity, duration, and quality of BMP effluent given the associated inflow values for a population of storm events. Analyses for this study were done with data extracted from a modified copy of the December 2019 version of the International Stormwater Best Management Practices Database. Statistics for volume reduction, hydrograph extension, and water-quality treatment were developed with selected data. The medians of the best-fit statistics for selected constituents were used to construct generalized cumulative distribution functions for the three treatment variables. For volume reduction and hydrograph extension, selection of a Spearman’s rank correlation coefficient (rho) value that is the average of the median and maximum values for the BMP category may help generate realistic simulation results in SELDM. The median rho value may be selected to help generate realistic simulation results for water-quality treatment variables. Water-quality treatment statistics, including trapezoidal ratios and MIC values, were developed for 51 runoff-quality constituents commonly measured in highway and urban runoff studies. Statistics were calculated for water-quality properties, sediment and solids, nutrients, major and trace inorganic elements, organic compounds, and biologic constituents. Analysis of MIC values provides information to guide professional judgement for selecting values for simulating water quality at sites of interest. The MIC is a lower bound for BMP discharge concentrations and will therefore replace simulated BMP discharge concentrations below the selected value. A new method for estimating MIC values, the lognormal variate of inflow concentrations, was developed in this report and these statistics were calculated for individual constituents and constituent categories. Inflow quality is correlated to MIC values for some constituents, but regional soil concentrations were not strongly correlated to MIC values.

Scientific Investigations Report↗
USGS2004

The application of an integrated biogeochemical model (PnET-BGC) to five forested watersheds in the Adirondack and Catskill regions of New York

PnET-BGC is an integrated biogeochemical model formulated to simulate the response of soil and surface waters in northern forest ecosystems to changes in atmospheric deposition and land disturbances. In this study, the model was applied to five intensive study sites in the Adirondack and Catskill regions of New York. Four were in the Adirondacks: Constable Pond, an acid-sensitive watershed; Arbutus Pond, a relatively insensitive watershed; West Pond, an acid-sensitive watershed with extensive wetland coverage; and Willy's Pond, an acid-sensitive watershed with a mature forest. The fifth was Catskills: Biscuit Brook, an acid-sensitive watershed. Results indicated model-simulated surface water chemistry generally agreed with the measured data at all five sites. Model-simulated internal fluxes of major elements at the Arbutus watershed compared well with previously published measured values. In addition, based on the simulated fluxes, element and acid neutralizing capacity (ANC) budgets were developed for each site. Sulphur budgets at each site indicated little retention of inputs of sulphur. The sites also showed considerable variability in retention of NO3-. Land-disturbance history and in-lake processes were found to be important in regulating the output of NO3- via surface waters. Deposition inputs of base cations were generally similar at these sites. Various rates of base cation outputs reflected differences in rates of base cation supply at these sites. Atmospheric deposition was found to be the largest source of acidity, and cation exchange, mineral weathering and in-lake processes served as sources of ANC. ?? 2004 John Wiley and Sons, Ltd.

Hydrological Processes↗
USGS1987

Potential for pollution of the Upper Floridan aquifer from five sinkholes and an internally drained basin in west-central Florida

Sinkholes are natural and common geologic features in west-central Florida, which is underlain by water soluble limestone deposits. Dissolution of these deposits is the fundamental cause of sinkhole development. Sinkholes and other karst features are more pronounced in the northern part of the study area, but sinkhole activity has occurred throughout the area. Fifty-eight sinkholes with known or suspected connection to the Upper Floridan aquifer are located in the study area. An internally drained basin near the city of Brandon and five sinkholes in Hillsborough, Pasco, and Hernando Counties were selected for detailed investigation. At all sites, chemical or biological constituents were detected that indicate pollutants had entered the aquifer. A generalized classification, based on the potential to pollute, was applied to the selected sites. Four of the sites have high potential and two have moderate potential to pollute the Upper Floridan aquifer. All of the sites investigated are capable of recharging large volumes of water to the Upper Floridan aquifer in short periods of time. Continued monitoring of the quality of water entering the sinkholes and of wells downgradient to the sinks is needed to assess the future impacts on the aquifer. (Author 's abstract)

Water-Resources Investigations Report↗
USGS2013

Framing scenarios of binational water policy with a tool to visualize, quantify and valuate changes in ecosystem services

In the Santa Cruz Watershed, located on the Arizona-Sonora portion of the U.S.-Mexico border, an international wastewater treatment plant treats wastewater from cities on both sides of the border, before discharging it into the river in Arizona. These artificial flows often subsidize important perennial surface water ecosystems in the region. An explicit understanding of the benefits of maintaining instream flow for present and future generations requires the ability to assess and understand the important trade-offs implicit in water-resource management decisions. In this paper, we outline an approach for modeling and visualizing impacts of management decisions in terms of rare terrestrial and aquatic wildlife, vegetation, surface water, groundwater recharge, real-estate values and socio-environmental vulnerable communities. We identify and quantify ecosystem services and model the potential reduction in effluent discharge to the U.S. that is under scrutiny by binational water policy makers and of concern to stakeholders. Results of service provisioning are presented, and implications for policy makers and resource managers are discussed. This paper presents a robust ecosystem services assessment of multiple scenarios of watershed management as a means to discern eco-hydrological responses and consider their potential values for future generations living in the borderlands.

Arizona;Sonora↗
USGS1982

Water-quality and hydrogeologic data for three phosphate industry waste-disposal sites in central Florida, 1979-80

This report is a complilation of geologic, hydrologic, and water-quality data and information on test holes collected in the vicinity of gypsum stack complexes at two phosphate chemical plants and one phosphatic clayey waste disposal pond at a phosphate mine and beneficiation plant in central Florida. The data were collected from September 1979 to October 1980 at thee AMAX Phosphate, Inc., chemical plant, Piney Point; the USS AgriChemicals chemical plant, Bartow; and the International Minerals and Chemical Corporation Clear Springs mine, Bartow. Approximmmtely 5,400 field and laboratory water-quality determinations on water samples were collected from about 78 test holes and 31 surface-water, rainfall, and other sampling sites at phosphate industry beneficiation and chemical plant waste-disposal operations. Maps show locations of sampling sites. (USGS)

Florida↗
USGS2009

Snow and ice in a changing hydrological world

On the occasion of the 60th anniversary of the International Association of Hydrological Sciences, the 100th and 50th anniversaries of the First and Second International Polar Years, and the 25th anniversary of the International Geophysical Year, it seems appropriate to re-examine the world's water balance and the role of snow and ice in the global hydrological climatic system. Snow cover on land (especially in the Northern Hemisphere) and sea ice (especially in the Southern Hemisphere) vary seasonally, and this seasonal change has an important effect on the world climate because snow and sea ice reflect solar radiation efficiently and affect other heat flow processes between atmosphere and land or ocean. Glaciers, including ice sheets, store most of the fresh water on Earth, but change dimensions relatively slowly. There is no clear evidence that the glacier ice volume currently is declining, but more needs to be known about mountain glacier and ice sheet mass balances. The current rise in sea level poses an enigma: thermal expansion of the oceans may account for half of the present rise, but the other half is unexplained. Although major changes in the large ice sheets take place over time scales of 10 4 to 10 5 years, marine ice sheets may be subject to rapid disintegration due to grounding line instability, perhaps accompanied by surging. Ice cores may produce remarkably complete histories of air temperature, precipitation, fallout, and atmospheric composition. A recent core through the Greenland Ice Sheet shows an abrupt transition from glacial to modern climate just over 10000 years ago, suggesting that climate is an “almost intransitive” system. Because of the possibility of abrupt climate transitions and the uncertain stability of the West Antarctic Ice Sheet, future climatic variations are difficult to predict. The calculated heating of the atmosphere in the polar regions due to CO 2 increase is, therefore, of special interest.

Hydrological Sciences Journal↗
USGS2007

Responses to riparian restoration in the Spring Creek watershed, Central Pennsylvania

Riparian treatments, consisting of 3- to 4-m buffer strips, stream bank stabilization, and rock-lined stream crossings, were installed in two streams with livestock grazing to reduce sediment loading and stream bank erosion. Cedar Run and Slab Cabin Run, the treatment streams, and Spring Creek, an adjacent reference stream without riparian grazing, were monitored prior to (1991-1992) and 3-5 years after (2001-2003) riparian buffer installation to assess channel morphology, stream substrate composition, suspended sediments, and macroinvertebrate communities. Few changes were found in channel widths and depths, but channel-structuring flow events were rare in the drought period after restoration. Stream bank vegetation increased from 50% or less to 100% in nearly all formerly grazed riparian buffers. The proportion of fine sediments in stream substrates decreased in Cedar Run but not in Slab Cabin Run. After riparian treatments, suspended sediments during base flow and storm flow decreased 47-87% in both streams. Macroinvertebrate diversity did not improve after restoration in either treated stream. Relative to Spring Creek, macroinvertebrate densities increased in both treated streams by the end of the posttreatment sampling period. Despite drought conditions that may have altered physical and biological effects of riparian treatments, goals of the riparian restoration to minimize erosion and sedimentation were met. A relatively narrow grass buffer along 2.4 km of each stream was effective in improving water quality, stream substrates, and some biological metrics. ?? 2007 Society for Ecological Restoration International.

Restoration Ecology↗
USGS2017

Inter-nesting movements and habitat-use of adult female Kemp’s ridley turtles in the Gulf of Mexico

Species vulnerability is increased when individuals congregate in restricted areas for breeding; yet, breeding habitats are not well defined for many marine species. Identification and quantification of these breeding habitats are essential to effective conservation. Satellite telemetry and switching state-space modeling (SSM) were used to define inter-nesting habitat of endangered Kemp’s ridley turtles ( Lepidochelys kempii ) in the Gulf of Mexico. Turtles were outfitted with satellite transmitters after nesting at Padre Island National Seashore, Texas, USA, from 1998 through 2013 (n = 60); Rancho Nuevo, Tamaulipas, Mexico, during 2010 and 2011 (n = 11); and Tecolutla, Veracruz, Mexico, during 2012 and 2013 (n = 11). These sites span the range of nearly all nesting by this species. Inter-nesting habitat lies in a narrow band of nearshore western Gulf of Mexico waters in the USA and Mexico, with mean water depth of 14 to 19 m within a mean distance to shore of 6 to 11 km as estimated by 50% kernel density estimate, α-Hull, and minimum convex polygon methodologies. Turtles tracked during the inter-nesting period moved, on average, 17.5 km/day and a mean total distance of 398 km. Mean home ranges occupied were 725 to 2948 km 2 . Our results indicate that these nearshore western Gulf waters represent critical inter-nesting habitat for this species, where threats such as shrimp trawling and oil and gas platforms also occur. Up to half of all adult female Kemp’s ridleys occupy this habitat for weeks to months during each nesting season. Because inter-nesting habitat for this species is concentrated in nearshore waters of the western Gulf of Mexico in both Mexico and the USA, international collaboration is needed to protect this essential habitat and the turtles occurring within it.

Gulf of Mexico↗
USGS2024

The U.S. Geological Survey Ohio Water Microbiology Laboratory

The U.S. Geological Survey Ohio Water Microbiology Laboratory is a part of the Ohio-Kentucky-Indiana Water Science Center. The mission of the laboratory is to provide microbiological data of public health significance from surface waters, groundwaters, and sediments for a variety of study objectives. The laboratory conducts internal projects, works with external cooperators, and assists U.S. Geological Survey offices and National programs. The laboratory offers guidance, study design, and data interpretation expertise to collaborators, all following rigorous quality control and quality assurance procedures.

Fact Sheet↗
USGS2005

External quality-assurance programs managed by the U.S. Geological Survey in support of the National Atmospheric Deposition Program/National Trends Network

The U.S. Geological Survey, Branch of Quality Systems, operates the external quality-assurance programs for the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Beginning in 1978, six different programs have been implemented?the intersite-comparison program, the blind-audit program, the sample-handling evaluation program, the field-audit program, the interlaboratory-comparison program, and the collocated-sampler program. Each program was designed to measure error contributed by specific components in the data-collection process. The intersite-comparison program, which was discontinued in 2004, was designed to assess the accuracy and reliability of field pH and specific-conductance measurements made by site operators. The blind-audit and sample-handling evaluation programs, which also were discontinued in 2002 and 2004, respectively, assessed contamination that may result from sampling equipment and routine handling and processing of the wet-deposition samples. The field-audit program assesses the effects of sample handling, processing, and field exposure. The interlaboratory-comparison program evaluates bias and precision of analytical results produced by the contract laboratory for NADP, the Illinois State Water Survey, Central Analytical Laboratory, and compares its performance with the performance of international laboratories. The collocated-sampler program assesses the overall precision of wet-deposition data collected by NADP/NTN. This report documents historical operations and the operating procedures for each of these external quality-assurance programs. USGS quality-assurance information allows NADP/NTN data users to discern between actual environmental trends and inherent measurement variability.

Open-File Report↗
USGS1996

Localized alteration of the paintbrush nonwelded hydrologic unit within the exploratory studies facility

The mound-like feature in the lower part of the PTn, composed of highly disrupted strata and open-system alteration were the result of intense water-rock interaction. This feature was formed by fumarolic activity during cooling of the 12.8 Ma Topopah Spring Tuff and prior to deposition of the pre-Pah Canyon bedded tuff. Evidence of vapor phase crystallization, commonly observed in fumaroles, is not pervasive but may have been destroyed by subsequent low-temperature water-rock interaction. The ESF has provided a unique opportunity to view the internal morphology and to sample the compositional variability of this feature, however, outcrop and borehole studies suggest that such localized occurrences of alterative are not uncommon phenomenon within the PTn Hydrology Unit.

Conference Paper↗
USGS1976

Thermal effects on fish ecology

Of all the environmental factors that influence aquatic organisms, temperature is the most all-pervasive. There is always an environmental temperature while other factors may or may not be present to exert their effects. Fish are, for all practical purposes, thermal conformers, or obligate poikilotherms. That is, they are able to exert little significant influence on maintaining a certain body temperature by specialized metabolic or behavioral means. Their body temperature thus fluctuates nearly in concert with the temperature of their aquatic medium (although particularly large, actively-moving fish such as tuna have deep muscle temperatures slightly higher than the water). Intimate contact at the gills of body fluids with the outside water and the high specific heat of water provide a very efficient heat exchanger that insures this near identity of internal and external temperatures.

Book chapter↗
USGS2003

Methods for quality-assurance review of water-quality data in New Jersey

This report is an instructional and reference manual that describes methods developed and used by the U.S. Geological Survey (USGS), New Jersey District, to assure the accuracy and precision of the results of analyses of surface- and ground-water samples received from analyzing laboratories and, ultimately, to ensure the integrity of water-quality data in USGS databases and published reports. A statistical-analysis computer program, COMP.PPL, is used to determine whether the values reported by the laboratories are internally consistent, whether they are reasonable when compared with values for samples previously collected at the same site, and whether they exceed applicable drinking-water regulations. The program output consists of three files -- QWREVIEW, QWOUTLIERS, and QWCALC. QWREVIEW presents the results of tests of chemical logic and shows values that exceed drinking-water regulations. QWOUTLIERS identifies values that fall outside the historical range of values for the site sampled. QWCALC shows values and calculations used for reference purposes. Because values that are identified by the program as questionable may or may not be in error, the reviewer looks at both qualitative and quantitative relations between analytes during the period of record and then uses technical judgement to decide whether to accept a questionable value or investigate further. Guidelines for, and the use of regression analysis in, making this decision are described. Instructions are given for requesting that the analyzing laboratory reanalyze a constituent or otherwise verify the reported value. If, upon reanalysis or verification, a value is still questionable, consideration must be given to deleting the value or marking the value in the USGS National Water Information System database as having been reviewed and rejected.

New Jersey↗