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At least 703 records · Page 39Linked to original sources

USGS2019

Streamflow Gain and Loss, Hydrograph Separation, and Water Quality of Abandoned Mine Lands in the Daniel Boone National Forest, Eastern Kentucky, 2015–17

During 2015–17, the U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service (Forest Service), carried out a study to characterize the hydrology and water chemistry in two study areas within the Daniel Boone National Forest. One study area was within the Rock Creek drainage and the other study area included the Wildcat and Addison Branch drainages. Both study areas historically were mined for coal prior to the Surface Mining Control and Reclamation Act of 1977 and contain abandoned coal mine sites that have since been the focus of remediation efforts. Synoptic surveys of streamflow and water-quality properties (water temperature, pH, specific conductance, and dissolved oxygen) of Rock Creek were done during November 2015 and May 2016, and surveys of Wildcat and Addison Branches were done during June 2016 and May 2017. Streamflow measurements were used to quantify contributions from tributaries and to compute streamflow gain and loss in designated reaches. Discrete measurements of water temperature, pH, specific conductance, and dissolved oxygen were used to evaluate conditions during a short timeframe and for comparison between study areas. Study designs for the two study areas differed because there was an operating streamgage on Rock Creek near Yamacraw, Kentucky (station number 03410590) where streamflow and water-quality properties (water temperature, specific conductance, pH, dissolved oxygen, and turbidity) were monitored continuously, while Addison and Wildcat Branches were ungaged. Several hydrograph separation methods were used to estimate base flow and runoff at the Rock Creek gage. These data will be used by the Forest Service to evaluate the current (2018) conditions and plan remediation efforts. The water quality at Rock Creek was less affected by acid mine drainage (AMD) than the Wildcat or Addison Branches. Appreciable losing reaches, where water flowed underground, were identified in both study areas. All losing reaches coincided with karst topography. Streamflow increased in areas with openings to underground mine tunnels, known as portals. Six hydrograph separation methods (Base-flow index [BFI; standard and modified], HYSEP [fixed interval, sliding interval, and local minimum], and PART) were applied to daily mean streamflow collected from August 2015 to August 2017 at station number 03410590. The hydrograph separation methods partition total streamflow into base flow and streamflow that originated from surface runoff. Base flow typically reacts slowly to precipitation infiltration and is largely sustained by groundwater discharge. The estimated daily base flow and runoff made with the different separation methods are not highly different. On average, base flow accounted for more total streamflow than surface runoff during the study period, irrespective of method. Water temperature, pH, dissolved oxygen, specific conductance, and turbidity values were measured from July 2016 through July 2017 with a continuous monitor installed at station number 03410590. Nearly neutral pH values that ranged from 6.8 to 7.9 standard units likely limited metal solubility in the surface water. The continuous specific conductance values ranged between 30 and 259 microsiemens per centimeter at 25 degrees Celsius. The previous remediation efforts are likely continuing to improve the effect of AMD in the study area.

Kentucky↗

USGS2025

Reviews and syntheses: Variable inundation across Earth's terrestrial ecosystems

The structure, function, and dynamics of Earth's terrestrial ecosystems are profoundly influenced by how often (frequency) and how long (duration) they are inundated with water. A diverse array of natural and human-engineered systems experience temporally variable inundation whereby they fluctuate between inundated and non-inundated states. Variable inundation spans extreme events to predictable sub-daily cycles. Variably inundated ecosystems (VIEs) include hillslopes, non-perennial streams, wetlands, floodplains, temporary ponds, tidal systems, storm-impacted coastal zones, and human-engineered systems. VIEs are diverse in terms of inundation regimes, water chemistry and flow velocity, soil and sediment properties, vegetation, and many other properties. The spatial and temporal scales of variable inundation are vast, ranging from sub-meter to whole landscapes and from sub-hourly to multi-decadal. The broad range of system types and scales makes it challenging to predict the hydrology, biogeochemistry, ecology, and physical evolution of VIEs. Despite all experiencing the loss and gain of an overlying water column, VIEs are rarely considered together in conceptual, theoretical, modeling, or measurement frameworks and approaches. Studying VIEs together has the potential to generate mechanistic understanding that is transferable across a much broader range of environmental conditions, relative to knowledge generated by studying any one VIE type. We postulate that enhanced transferability will be important for predicting changes in VIE function in response to global change. Here we aim to catalyze cross-VIE science that studies drivers and impacts of variable inundation across Earth's VIEs. To this end, we complement expert mini-reviews of eight major VIE systems with overviews of VIE-relevant methods and challenges associated with scale. We conclude with perspectives on how cross-VIE science can derive transferable understanding via unifying conceptual models in which the impacts of variable inundation are studied across multi-dimensional environmental space.

Biogeosciences↗

USGS2012

Redox reaction rates in shallow aquifers: Implications for nitrate transport in groundwater and streams

Groundwater age and water chemistry data along flow paths from recharge areas to streams were used to evaluate the trends and transformations of agricultural chemicals. Results from this analysis indicate that median nitrate recharge concentrations in these agricultural areas have increased markedly over the last 50 years from 4 mg N/L in samples collected prior to 1983 to 7.5 mg N/L in samples collected since 1983. The effect that nitrate accumulation in shallow aquifers will have on drinking water quality and stream ecosystems is dependent on the rate of redox reactions along flow paths and on the age distribution of nitrate discharging to supply wells and streams.

Conference Paper↗

USGS2003

Aquifer Susceptibility in Virginia: Data on Chemical and Isotopic Composition, Recharge Temperature, and Apparent Age of Water from Wells and Springs, 1998-2000

The determination of aquifer susceptibility to contamination from near-surface sources by the use of ground-water dating techniques is a critical part of Virginia's Source Water Assessment Program. As part of the Virginia Aquifer Susceptibility study, water samples were collected between 1998 and 2000 from 145 wells and 6 springs in various hydrogeologic settings across the Commonwealth. Samples were analyzed to determine water chemistry?including nitrate (NO3), dissolved organic carbon (DOC), and radon-222 (222Rn), major dissolved and noble gases?nitrogen (N2), argon (Ar), oxygen (O2), carbon dioxide (CO2), methane (CH4), helium (He), and neon (Ne), environmental tracers?chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), tritium (3H), and tritium/helium-3 (3H/3He), carbon isotopes?carbon-14 (14C) and carbon-13 (d13C), and stable isotopes of oxygen (d18O) and hydrogen (d2H). The chemical and isotopic composition, recharge temperatures, and apparent ages of these water samples are presented in this report. Data collected between 1999 and 2000 from 18 wells in Virginia as part of two other studies by the U.S. Geological Survey also are presented. Most of the sites sampled serve as public water supplies and are included in the comprehensive Source Water Assessment Program for the Commonwealth.

Open-File Report↗

USGS2002

Ground-water resources of the Clifton Park area, Saratoga County, New York

Ground water is the sole source of public water supply for Clifton Park, a growing suburban community north of Albany, New York. Increasing water demand, coupled with concerns over ground-water quantity and quality, led the Clifton Park Water Authority in 1995 to initiate a cooperative study with the U.S. Geological Survey to update and refine the understanding of ground-water resources in the area. Ground-water resources are largely associated with three aquifers in the eastern half of the area. These aquifers overlie or encompass the Colonie Channel, a north-south-oriented bedrock channel that is filled primarily with lacustrine glacial deposits. The three aquifers are: (1) an unconfined lacustrine sand aquifer, (2) the Colonie Channel aquifer, which is confined within the deepest parts of the channel and variably confined and unconfined within the shallower, peripheral channel areas, and (3) an unconfined alluvial aquifer beneath the Mohawk River flood plain, which represents the southern limit of the study area. The lacustrine sand aquifer has little potential for large-scale withdrawals because it is predominantly fine grained and is susceptible to contamination from human activities at land surface. Water from this aquifer can, however, recharge the underlying peripheral parts of the Colonie Channel aquifer where hydraulic connections are present. The Colonie Channel aquifer consists of thin sand and gravel and (or) shallow, fractured bedrock over much of the channel area; discontinuous deposits of thicker (more than 20 feet) sand and gravel are common in the peripheral channel areas. The deepest, or central, channel area of this aquifer is isolated from the overlying lacustrine sand aquifer by a continuous lacustrine silt and clay unit, which is the primary channel-fill deposit. The most productive areas of the Colonie Channel aquifer are typically the shallow peripheral areas, where conditions range from unconfined to confined. The most productive aquifer within the area is the alluvial aquifer, which is sustained to an unknown extent by induced infiltration of Mohawk River water. The chemical composition of ground water within the Clifton Park area varies widely in response to hydrogeologic setting, pumpage, and contamination from human activities. These chemical differences can be used to deduce ground-water flow paths within and between the unconfined and confined areas of the aquifer system. Six water types are defined; three are naturally occurring and three are the result of human activities. Precipitation that infiltrates the land surface is the sole source of recharge to the lacustrine sand aquifer; precipitation also recharges the alluvial aquifer and unconfined parts of the Colonie Channel aquifer. Ground-water withdrawals from confined or unconfined peripheral areas of the Colonie Channel aquifer induce flow from recharge areas, from the underlying bedrock, or from other confined aquifer areas. The rate of recharge to the confined central area of the Colonie Channel aquifer appears to be low. Potentiometric levels as much as 100 feet below water-table levels in the overlying lacustrine sand aquifer indicate two large depressions in the potentiometric surface; these depressions indicate that withdrawals from this aquifer have cumulatively exceeded the recharge rates. Localized recharge of the central channel area apparently occurs from two peripheral channel areas that are characterized by zones of elevated water levels and (or) by water chemistry that differs from those within the central channel area. Recharge from, or hydraulic connection with, adjoining segments of the Colonie Channel aquifer to the north and south is likely, but the potential for significant recharge is low because the aquifer is thin and poorly permeable.

New York↗

USGS1997

Stream habitat characteristics of fixed sites in the western Lake Michigan drainages, Wisconsin and Michigan, 1993-95

Habitat characteristics of 11 fixed sites in the Western Lake Michigan Drainages were examined by the U.S. Geological Survey from 1993 through 1995 as part of the ecological assessment of the National Water-Quality Assessment Program. Evaluation of habitat consisted of more than 75 measurements at three spatial levels: drainage basin, stream segment between major tributaries (length from 1 to 14 kilometers), and stream reach (approximately 150 meters). The 11 fixed sites consisted of 8 "indicator" sites with drainage basins that differ in bedrock type, surficial deposits, and land use; and 3 "integrator" sites with drainage basins that contain a mixture of bedrock type, surficial deposits, and land use. Spatial and temporal variations in habitat characteristics are described and compared. Comparisons are limited to indicator sites except for comparisons amongbasin characteristics, which include all fixed sites. Two habitat classification schemes used in Wisconsin and Michigan were used to rank the quality of habitat in indicator streams. Reach-level data were collected at two additional reaches at three of the indicator sites to assess the representativeness of the reach for overall stream conditions. Although the number of sites is small, statistical analyses indicate that spatial distribution of several characteristics can be related to land use, geology, topography, and width of the riparian zone. Land use and geology, in combination, appeared to be important factors in controlling flood magnitudes. Annual mean flow was correlated with basin shape and drainage density and low flow was correlated with permeability of soils in the basin. At the reach level, a wide variety of characteristics were observed at the eight indicator sites, with many of the characteristics significantly different between sites. Spatial differences in some reach characteristics can be attributed to the percentage of agriculture in the drainage basin, type of surficial deposits, and width of the riparian zone. Temporal variability in width, depth, and velocity can be attributed to variable flow conditions; whereas temporal variability in streambank measurements are attributed to problematic identification of the boundary between the flood plain and streambanks. Data from multiple-reach sites indicate that the primary reach adequately represented the variability found within the stream segment for depth, streambank stability index, and canopy angle. However, velocity, dominant substrate type, embeddedness, streambank height, streambank angle, and streambank vegetative stability differed among the multiple reaches at one or more of the three sites. Correlation analyses of habitat characteristics with median concentrations of four nutrients, pH, and specific conductance indicates that dissolved nitrate plus nitrite concentrations are related to percentage of agriculture in the basin and fine-grained sediment deposition in the reach. Geology and land use appear to be major influences on pH, but their influence on specific conductance, although expected, was not confirmed in this study. Habitat evaluation scores at the eight indicator sites ranged from poor to good. Scores were correlated to the percentage of agricultural or urban land in the drainage basins, width of the riparian zone, and streambank stability index. Results from this study illustrate the need for collection of habitat data at multiple scales along with water-chemistry data for determining major influences on distribution of aquatic communities. These results also indicate the importance of collecting land use, geological, and geomorphic information at the drainage-basin level to adequately describe how natural and human factors influence local aquatic habitat conditions.

Michigan, Wisconsin↗

USGS2017

Guidance documents: Continued support to improve operations of fish hatcheries and field sites to reduce the impact or prevent establishment of New Zealand Mudsnails and other invasive mollusks

This project tested and revised a risk assessment/management tool authored by Moffitt and Stockton designed to provide hatchery biologists and others a structure to measure risk and provide tools to control, prevent or eliminate invasive New Zealand mudsnails (NZMS) and other invasive mollusks in fish hatcheries and hatchery operations. The document has two parts: the risk assessment tool, and an appendix that summarizes options for control or management. The framework of the guidance document for risk assessment/hatchery tool combines approaches used by the Hazard Analysis and Critical Control Points (HACCP) process with those developed by the Commission for Environmental Cooperation (CEC), of Canada, Mexico, and the United States, in the Tri-National Risk Assessment Guidelines for Aquatic Alien Invasive Species. The framework approach for this attached first document assesses risk potential with two activities: probability of infestation and consequences of infestation. Each activity is treated equally to determine the risk potential. These two activities are divided into seven basic elements that utilize scientific, technical, and other relevant information in the process of the risk assessment. To determine the probability of infestation four steps are used that have scores reported or determined and averaged. This assessment follows a familiar HACCP process to assess pathways of entry, entry potential, colonization potential, spread potential. The economic, environmental and social consequences are considered as economic impact, environmental impact, and social and cultural influences. To test this document, the Principal Investigator worked to identify interested hatchery managers through contacts at regional aquaculture meetings, fish health meetings, and through the network of invasive species managers and scientists participating in the Western Regional Panel on Aquatic Nuisance Species and the 100th Meridian Initiative's Columbia River Basin Team, and the Western New Zealand Mudsnail Conference in Seattle. Targeted hatchery workshops were conducted with staff at Dworshak National Fish Hatchery Complex (ID), Similkameen Pond, Oroville WA, and Ringold Springs State Hatchery (WA). As a result of communications with hatchery staff, invasive species managers, and on site assessments of hatchery facilities, the document was modified and enhanced. Additional resources were added to keep it up to date. The result is a more simplified tool that can lead hatchery or management personnel through the process of risk assessment and provide an introduction to the risk management and communication process. In addition to the typical HACCP processes, this tool adds steps to rate and consider uncertainty and the weight of evidence regarding options and monitoring results . Uncertainty of outcome exists in most tools that can be used to control or prevent NZMS or other invasive mollusks from infesting an area. In additional this document emphasizes that specific control tools and plans must be tailored to each specific setting to consider the economic, environmental and social influences. From the testing and evaluation process, there was a strong recognition that a number of control and prevention tools previously suggested and reported in the literature from laboratory and small scale trials may not be compatible with regional and national regulations, economic constraints, social or cultural constraints, engineering or water chemistry characteristics of each facility. The options for control are summarized in the second document, Review of Control Measures for Hatcheries Infested with NZMS (Appendix A) that provides sources for additional resources and specific tools, and guidance regarding the feasibility and success of each approach. This tool also emphasizes that management plans need to be adaptive and incorporate oversight from professionals familiar with measuring risks of fish diseases, and treatments (e.g. the fish health practitioners and water quality and effluent management teams). Finally, with such a team, the adaptive management approach must be ongoing, and become a regular component of hatchery operations. Although it was the intent that this two part document would be included as part of the revised National Management and Control Plan for the NZMS proposed by the U.S. Fish and Wildlife Service (USFWS) and others, it is provided as a stand-alone document.

Cooperator Science Series↗

USGS2021

The impact of ventilation patterns on calcite dissolution rates within karst conduits

Erosion rates in streams vary dramatically over time, as differences in streamflow and sediment load enhance or inhibit erosion processes. Within cave streams, and other bedrock channels incising soluble rocks, changes in water chemistry are an important factor in determining how erosion rates will vary in both time and space. Prior studies in surface streams, springs, and caves suggest that variation in dissolved CO 2 is the strongest control on variation in calcite dissolution rates. However, the controls on CO 2 variation remain poorly quantified. Limited data suggest that ventilation of karst systems can substantially influence dissolved CO 2 within karst conduits. However, the interactions among cave ventilation, air-water CO 2 exchange, and dissolution dynamics have not been studied in detail. In this study, three years of time series measurements of dissolved and gaseous CO 2 , cave airflow velocity, and specific conductance from Blowing Springs Cave, Arkansas, were analyzed and used to estimate continuous calcite dissolution rates and quantify the correlations between those rates and potential physical and chemical drivers. We find that chimney effect airflow creates temperature-driven switches in airflow direction, and that the resulting seasonal changes in airflow regulate both gaseous and dissolved CO 2 within the cave. As in previous studies, partial pressure of CO 2 ( p CO 2 ) is the strongest chemical control of dissolution rate variability. However, we also show that cave airflow direction, rather than streamflow, is the strongest physical driver of changes in dissolution rate, contrary to the typical situation in surface channel erosion where floods largely determine the timing and extent of geomorphic work. At the study site, chemical erosion is typically active in the summer, during periods of cave downdraft (airflow from upper to lower entrances), and inactive in the winter, during updraft (airflow from lower to upper entrances). Storms provide only minor perturbations to this overall pattern. We also find that airflow direction modulates dissolution rate variation during storms, with higher storm variability during updraft than during downdraft. Finally, we compare our results with the limited set of other studies that have examined dissolution rate variation within cave streams and draw an initial hypothesis that evolution of cave ventilation patterns strongly impacts how dissolution rate dynamics evolve over the lifetime of karst conduits.

Arkansas, Missouri↗

USGS1988

Experimental studies in stream-aquifer interaction along the Arkansas River in Central Kansas - Field testing and analysis

During the last several years, streamflows of a number of Kansas streams have been reduced as a result of groundwater declines. In order to better understand and quantify stream-aquifer interrelationships, an eight-day comprehensive stream-aquifer pumping test, followed by recovery monitoring, was conducted along the Arkansas River near Great Bend, Kansas. In addition to water level monitoring in numerous observation wells, streamflow data, streambed hydraulic gradients, neutron probe-based water content of dewatered sediments, water chemistry and other data were collected. The alluvial aquifer is shown to be highly transmissive ( T = 1803 m 2 d −1 ) with the pumping stress (9538 m 3 d −1 ) having a radius of influence larger than 1.77 km, impacting both the aquifer levels and the streamflow in the nearby Arkansas River. Drawdown and recharge boundary effects were observed in all observation wells, including those on the opposite side of the river. The alluvial aquifer did not exhibit a water table behavior and responded as a leaky confined aquifer. A semiconfining clay layer less than 3 m thick and an additional recharge source from a nearby stream-alluvial system were the probable causes of the observed phenomena. Actual streamflow depletion is shown to be appreciably less than the computed depletion based on analytical solutions.

Kansas↗

USGS1982

Impact of Mount St. Helens eruption on hydrology and water quality

The 1980 eruptions of Mount St. Helens in southeast Washington resulted in a pronounced effect on the surface and ground water resources of the state. In response to the volcanic activity, the U.S. Geological Survey intensified statewide surface and ground water sampling programs to determine the nature and magnitude of the volcanic-induced variations. Streams to the east of Mount St. Helens received the major ash fallout. Chemical effects were best noted in smaller streams sampled 60 to 70 miles northeast of Mount St. Helens. The chemical variations observed were pronounced but short lived. Sulfate and chloride increases in anionic composition were prevalent immediately following the eruption however, the original bicarbonate predominance was again attained within several days. Suspended iron and aluminum concentrations were similarly elevated during the period of greatest ash deposition (highest turbidity) however, the dissolved concentrations remained relatively constant. Depressions of pH were minor and short lived. Streams draining to the south, tributaries to the Columbia river, showed little observable changes in water chemistry. Streams draining to the west (Toutle river and its tributaries) were compositionally affected by the various volcanic activities. Chloride and sulfate anion percentage exceeded the bicarbonate percentage up to one month following the eruption period. Streams and lakes sampled in the immediate vicinity of Mount St. Helens, in addition to trace metals, contained organic compounds derived from decomposing wood buried in the debris deposits. This organic material may constitute a significant source of organic compounds to surface and ground water for some time to come.

Washington↗

USGS2015

Copper toxicity and organic matter: Resiliency of watersheds in the Duluth Complex, Minnesota, USA

We estimated copper (Cu) toxicity in surface water with high dissolved organic matter (DOM) for unmined mineralized watersheds of the Duluth Complex using the Biotic Ligand Model (BLM), which evaluates the effect of DOM, cation competition for biologic binding sites, and metal speciation. A sediment-based BLM was used to estimate stream-sediment toxicity; this approach factors in the cumulative effects of multiple metals, incorporation of metals into less bioavailable sulfides, and complexation of metals with organic carbon. For surface water, the formation of Cu-DOM complexes significantly reduces the amount of Cu available to aquatic organisms. The protective effects of cations, such as calcium (Ca) and magnesium (Mg), competing with Cu to complex with the biotic ligand is likely not as important as DOM in water with high DOM and low hardness. Standard hardness-based water quality criteria (WQC) are probably inadequate for describing Cu toxicity in such waters and a BLM approach may yield more accurate results. Nevertheless, assumptions about relative proportions of humic acid (HA) and fulvic acid (FA) in DOM significantly influence BLM results; the higher the HA fraction, the higher calculated resiliency of the water to Cu toxicity. Another important factor is seasonal variation in water chemistry, with greater resiliency to Cu toxicity during low flow compared to high flow. Based on generally low total organic carbon and sulfur content, and equivalent metal ratios from total and weak partial extractions, much of the total metal concentration in clastic streambedsediments may be in bioavailable forms, sorbed on clays or hydroxide phases. However, organicrich fine-grained sediment in the numerous wetlands may sequester significant amount of metals, limiting their bioavailability. A high proportion of organic matter in waters and some sediments will play a key role in the resiliency of these watersheds to potential additional metal loads associated with future mining operations.

Minnesota↗

USGS1997

Streamflow and sediment data collected to determine the effects of a controlled flood in March and April 1996 on the Colorado River between Lees Ferry and Diamond Creek, Arizona

An 8-day period of planned release of water at 1,275 cubic meters per second from Glen Canyon Dam in March and April 1996 provided an opportunity to collect data on river stage, streamflow, water chemistry, and sediment transport at discharges above powerplant releases. The U.S. Geological Survey collected data at five streamflow-gaging stations on the mainstem of the Colorado River and four on tributaries during the controlled flood. River-stage data were collected at an additional 29 locations, and suspended-sediment data were collected at 4 of the 5 mainstem streamflow-gaging stations. In addition, measurements of reach-average flow velocity were made using a dye tracer, and water-surface slope was measured in reaches adjacent to three of the streamflow-gaging stations. Sand-storage changes caused by the controlled flood were documented by measuring bed elevation of the channel at cross sections before and after the controlled releases at the network of 120 monumented locations. This report presents selected data in tabular and graphical form. The data presented in the report are available in electronic form.

Open-File Report↗

USGS2023

Yellowstone Volcano Observatory 2022 annual report

The Yellowstone Volcano Observatory (YVO) monitors volcanic and hydrothermal activity associated with the Yellowstone magmatic system, carries out research into magmatic processes occurring beneath Yellowstone Caldera, and issues timely warnings and guidance related to potential future geologic hazards. This report summarizes the activities and findings of YVO during the year 2022, focusing on the Yellowstone volcanic system. Highlights of YVO research and related activities during 2022 include deployments of seismometers in Norris Geyser Basin and Upper Geyser Basin to investigate interactions between hydrothermal features and influences from external influences, geological studies of post-glacial hydrothermal activity, refining the ages of Yellowstone volcanic units and updating existing maps of geologic deposits, new mapping of ash-flow deposits on the Sour Creek dome, installation of a new continuous gas monitoring station near Mud Volcano, sampling of gas emissions and thermal waters around Yellowstone National Park to monitor water chemistry over space and time, research into the age and history of Steamboat Geyser in Norris Geyser Basin, and assessment of thermal output based on satellite imagery and chloride flux in rivers. The most noteworthy event of the year was not geophysical, but meteorological. Combined runoff from rain and snowmelt caused substantial flooding in Yellowstone National Park, which caused damage to park roads and infrastructure. Steamboat Geyser, in Norris Geyser Basin, continued the pattern of frequent eruptions that began in 2018 with 11 water eruptions in 2022, the lowest number of annual eruptions in the current eruptive sequence. Total seismicity—2,429 located earthquakes—was slightly less than the 2,773 earthquakes located in 2021 and at the upper end of the historical average range of about 1,500–2,500 earthquakes per year. Overall subsidence of the caldera floor, ongoing since late 2015 or early 2016, continued at rates of a few centimeters (1–2 inches) per year. Satellite deformation measurements indicated the possibility of slight uplift amounting to about 1 centimeter (less than 1 inch) along the north caldera rim in 2021, but satellite data spanning 2022 show no uplift in that area. Throughout 2022, the aviation color code for Yellowstone Caldera remained at “green” and the volcano alert level remained at “normal.”

Wyoming↗

USGS1984

Geohydrologic and drill-hole data for test well USW H-4, Yucca Mountain, Nye County, Nevada

Data are presented on drilling operations, lithology, geophysical well logs, sidewall-core samples, water-level monitoring, pumping tests, injection tests, radioactive-tracer borehole flow survey, and water chemistry for test well USW H-4. The well is one of a series of test wells drilled in the southwestern part of the Nevada Test Site, Nye County, Nevada, in cooperation with the U.S. Department of Energy. These test wells are part of the Nevada Nuclear Waste Storage Investigations to identify sites for storage of high-level radioactive wastes. Test well USW H-4 was drilled in ash-flow tuff to a total depth of 1,219 meters. Depth to water below land surface was 519 meters or at an altitude of 730 meters above sea level. After test pumping at a rate of 17.4 liters per second for approximately 9 days, the drawdown was 4.85 meters. A radioactive borehole-flow survey indicated that the Bullfrog Member was the most productive geologic unit, producing 36.5 percent of the water in the well. The second most productive geologic unit was the Tram Member, which produced 32 percent of the water. The water in test well USW H-4 is predominantly a soft, sodium bicarbonate type of water typical of water produced in tuffaceous rocks in southern Nevada. (USGS)

Open-File Report↗

USGS1997

Use of geochemical mass balance modelling to evaluate the role of weathering in determining stream chemistry in five mid-Atlantic watersheds on different lithologies

The importance of mineral weathering was assessed and compared for five mid-Atlantic watersheds receiving similar atmospheric inputs but underlain by differing bedrock. Annual solute mass balances and volume-weighted mean solute concentrations were calculated for each watershed for each year of record. In addition, primary and secondary mineralogy were determined for each of the watersheds through analysis of soil samples and thin sections using petrographic, scanning electron microscope, electron microprobe and X-ray diffraction techniques. Mineralogical data were also compiled from the literature. These data were input to NETPATH, a geochemical program that calculates the masses of minerals that react with precipitation to produce stream water chemistry. The feasibilities of the weathering scenarios calculated by NETPATH were evaluated based on relative abundances and reactivities of minerals in the watershed. In watersheds underlain by reactive bedrocks, weathering reactions explained the stream base cation loading. In the acid-sensitive watersheds on unreactive bedrock, calculated weathering scenarios were not consistent with the abundance of reactive minerals in the underlying bedrock, and alternative sources of base cations are discussed.

Hydrological Processes↗

USGS2005

Influence of fracture anisotropy on ground water ages and chemistry, Valley and Ridge province, Pennsylvania

Model ground water ages based on chlorofluorocarbons (CFCs) and tritium/helium-3 (3H/3He) data were obtained from two arrays of nested piezometers located on the north limb of an anticline in fractured sedimentary rocks in the Valley and Ridge geologic province of Pennsylvania. The fracture geometry of the gently east plunging fold is very regular and consists predominately of south dipping to subhorizontal to north dipping bedding-plane parting and east striking, steeply dipping axial-plane spaced cleavage. In the area of the piezometer arrays, which trend north-south on the north limb of the fold, north dipping bedding-plane parting is a more dominant fracture set than is steeply south dipping axial-plane cleavage. The dating of ground water from the piezometer arrays reveals that ground water traveling along paths parallel to the dip direction of bedding-plane parting has younger 3H/3He and CFC model ages, or a greater component of young water, than does ground water traveling along paths opposite to the dip direction. In predominantly unmixed samples there is a strong positive correlation between age of the young fraction of water and dissolved sodium concentration. The travel times inferred from the model ages are significantly longer than those previously calculated by a ground water flow model, which assumed isotropically fractured layers parallel to topography. A revised model factors in the directional anisotropy to produce longer travel times. Ground water travel times in the watershed therefore appear to be more influenced by anisotropic fracture geometry than previously realized. This could have significant implications for ground water models in other areas underlain by similarly tilted or folded sedimentary rock, such as elsewhere in the Valley and Ridge or the early Mesozoic basins.

Pennsylvania↗

USGS2024

Ecology of Lake Erie - Chemistry, plankton & planktivory: A synthesis

As with other large lake ecosystems worldwide, Lake Erie can be considered a moving target for management, owing to physicochemical and biological changes brought on by anthropogenic change, both planned (e.g. nutrient and fisheries management) and unplanned (e.g. climate change, invasive species, modified land-use activities). These changes have challenged efforts to conserve biodiversity, sustain exploitable resources, and maintain the integrity of services valued by society both within the Lake Erie basin and (Fraker et al., 2022; Fussell et al., 2016; Sinclair et al., 2021; Sinclair et al., 2023) and outside of it (Allan et al., 2013; Jenny et al., 2020; Sterner et al., 2017). Some of these changes and their ramifications for management were documented in the first of four AEHM special issues devoted to the Lake Erie ecosystem (the fourth issue of 2023, volume 26, issue 4; see overview by Ludsin et al., 2023). That special issue focused explicitly on nutrient inputs and availability in Lake Erie and the lower food web, including planktonic and benthic microbial (including cyanobacteria), algal, and invasive dreissenid mussel communities. Similar to the previous Lake Erie special issue, this second one has focused on documenting the state of the lake, providing ecological understanding that could potentially benefit management. While some overlap in topics exists between issues, the studies conducted herein were completely independent of those previous investigations and offer unique insights. Specifically, the contributions to this current issue center on: 1) dynamics of water chemistry in Lake Erie’s central basin (i.e. bottom hypoxia; Ackerman et al., 2024) and western basin (i.e. mercury; Starr et al., 2024); 2) changes in primary producer biomass (Lesht et al., 2024), cyanotoxins (i.e. microcystin; Zastepa et al., 2024), and water quality (e.g. water clarity and dissolved nutrients; Howell et al., 2024); and 3) larval fish foraging (i.e. Lake Whitefish; Coregonus clupeaformis; Amidon et al., 2024) and community structure and phenology (DeBruyne et al., 2024). Below we summarize the major findings of these papers and offer a synthetic perspective on the value of this research for understanding the state of Lake Erie and enhancing management.

Aquatic Ecosystem Health and Management↗

USGS2015

Geochemical conditions and the occurrence of selected trace elements in groundwater basins used for public drinking-water supply, Desert and Basin and Range hydrogeologic provinces, 2006-11: California GAMA Priority Basin Project

The geochemical conditions, occurrence of selected trace elements, and processes controlling the occurrence of selected trace elements in groundwater were investigated in groundwater basins of the Desert and Basin and Range (DBR) hydrogeologic provinces in southeastern California as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP is designed to provide an assessment of the quality of untreated (raw) groundwater in the aquifer systems that are used for public drinking-water supply. The GAMA PBP is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The DBR hydrogeologic provinces consist of 141 defined groundwater basins separated by mountain ranges, faults, and other features. This report presents analyses of data collected from nine study areas within the DBR hydrogeologic provinces: Antelope Valley, Borrego Valley, the Central Desert area, Coachella Valley, Colorado River, Indian Wells Valley, Low-Use Basins of the Mojave and Sonoran Deserts, the Mojave, and Owens Valley. Collectively, these nine study areas are referred to as the DBR study unit. The study unit covers approximately 7,000 square miles and includes the 63 groundwater basins in the DBR hydrogeologic provinces in which groundwater is used for public drinking-water supply. The vast majority of the 223 wells sampled for this study were long-screened production wells used primarily for public supply. Uncorrected carbon-14 ( 14 C) groundwater ages for samples collected in the DBR study unit ranged from less than (<) 100 to 33,700 years before present (BP). Sixty-six percent of sample ages were greater than (>) 100 years BP, and 40 percent were >3,800 years BP. Samples collected from wells located adjacent to mountain-front recharge areas or major surface-water features generally had younger groundwater ages than did samples collected from wells located away from mountain fronts or towards the distal ends of basin groundwater flow paths. Most groundwater sampled in the DBR study unit had alkaline pH: 89 percent of sample pH values ranged from 7.1 to 9.8, with 37 percent greater than or equal to (≥) 7.9. Groundwater age was significantly correlated (positively) with pH, likely because silicate weathering is a primary control on groundwater pH and is a slow process. The oxidation-reduction (redox) condition of the groundwater sampled in the DBR study unit was predominantly oxic (71 percent), except in the Colorado River study area where organic-rich fluvial aquifers provide the electron donors necessary to support iron-reducing (anoxic-Fe) redox processes. The cation type of 78 percent of the samples was either sodium- or mixed-type, and the anion type of 83 percent of the samples was either bicarbonate- or mixed-type. Sodium-type groundwaters generally were older and more alkaline than calcium-type groundwaters, consistent with the change in water chemistry expected from cation exchange between groundwater and aquifer sediments over long periods of time. Because of the correlation with young groundwater, calcium-type groundwater was predominantly from wells located adjacent to mountain-front recharge areas. Arsenic (As), boron (B), fluoride (F), molybdenum (Mo), strontium (Sr), uranium (U), and vanadium (V) were selected for assessment in this study because they occurred at concentrations greater than California Department of Public Health or U.S. Environmental Protection Agency regulatory or non-regulatory drinking-water-quality benchmarks in more than 2 percent of the 223 samples collected in the DBR study unit. As and F were detected most commonly (18 and 13 percent, respectively) at concentrations above associated water-quality benchmarks and Sr and V least frequently (both at 3 percent). Given that 14 C groundwater ages are predominantly >100 years BP, land use in the study unit is primarily undeveloped, and chemicals derived from anthropogenic sources, such as volatile organic compounds, were infrequently detected, high concentrations of these trace elements in groundwater were most likely the result of natural factors and not anthropogenic factors. As, F, Mo, and V concentrations showed significant positive correlations to groundwater age and to pH. This relation is partly due to the sources of trace elements likely being the weathering of primary minerals, such as silicate minerals, which is a slow process that takes place over hundreds to thousands of years. This relation also reflects the positive correlation between groundwater age and pH. Geochemical modeling predicted that the dominant species of As, Mo, and V in solution were oxyanions (HAsO 4 2– , MoO 4 2– , and H 2 VO 4– ), which are likely to be mobile in alkaline groundwater because mineral surfaces composing aquifer matrices have a predominantly negative surface charge under alkaline conditions. F also exists predominantly as a negatively charged ion (F – ). At pH values >7.5, saturation indices generated by the geochemical modeling program PHREEQC indicated that F solubility may be somewhat limited by the precipitation of the mineral fluorapatite [Ca 5 (PO 4 ) 3 F]. Speciation modeling of As in anoxic-Fe groundwater (iron-reducing conditions) showed that samples were supersaturated with orpiment (As 2 S 3 ), indicating that mineral precipitation may be responsible for low As concentrations observed in reducing groundwater. In contrast, U concentrations showed significant negative correlations to groundwater age and to pH. Higher U concentrations generally occurred in samples for which geochemical modeling indicated that the uncharged ternary complex Ca 2 UO 2 (CO 3 ) 3 was the dominant aqueous U species. This uncharged complex is not attracted to the charged surfaces of minerals and thus increases U solubility. Formation of Ca 2 UO 2 (CO 3 ) 3 was greater in younger groundwaters because calcium and uranium concentrations generally were lower in older groundwaters, likely due to cation-exchange processes and precipitation of the mineral calcite as groundwater pH increased. Co-precipitation of U with the calcite (CaCO 3 ) may remove U from the aqueous phase. Saturation indices indicated that the anoxic-Fe groundwaters from the Colorado River study area were supersaturated with the mineral uraninite (UO 2 ), suggesting that UO 2 precipitation may be responsible for the low concentrations of U observed in these samples. Concentrations of strontium, which exists primarily in a cationic form (Sr 2+ ), were not significantly correlated with either groundwater age or pH. Strontium concentrations showed a strong positive correlation with total dissolved solids (TDS). Dissolved constituents, such as Sr, that interact with mineral surfaces through outer-sphere complexation become increasingly soluble with increasing TDS concentrations of groundwater. Boron concentrations also showed a significant positive correlation with TDS, indicating the B may interact to a large degree with mineral surfaces through outer-sphere complexation.

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