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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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USGS2022

Contaminant fluxes across ecosystems mediated by aquatic insects

Metals and organic contaminants in aquatic systems affect the coupling of aquatic and terrestrial ecosystems through two pathways: contaminant-induced effects on insect emergence and emergence-induced contaminant transfer. Consequently, the impact of aquatic contaminants on terrestrial ecosystems can be driven by modifications in the quantity and quality of adult aquatic insects serving as prey or contaminants entering terrestrial food webs as part of the diet of terrestrial predators. Here, we provide an overview of recent advances in the field, separating metals from organic contaminants due to their differential propensity to bioaccumulate and thus their potential contribution to either of the two pathways. Finally, this review highlights the knowledge gap in the relative impact of these pathways on terrestrial insectivores.

Current Opinion in Insect Science↗

USGS2017

Cooperative science to inform Lake Ontario management: Research from the 2013 Lake Ontario CSMI program

Since the mid-1970s, successful Lake Ontario management actions including nutrient load and pollution reductions, habitat restoration, and fish stocking have improved Lake Ontario. However, several new obstacles to maintenance and restoration have emerged. This special issue presents management-relevant research from multiple agency surveys in 2011 and 2012 and the 2013 Cooperative Science and Monitoring Initiative (CSMI), that span diverse lake habitats, species, and trophic levels. This research focused on themes of nutrient loading and fate; vertical dynamics of primary and secondary production; fish abundance and behavior; and food web structure. Together these papers identify the status of many of the key drivers of the Lake Ontario ecosystem and contribute to addressing lake-scale questions and management information needs in Lake Ontario and the other Great Lakes and connecting water bodies.

Lake Ontario↗

USGS2006

Urban contributions of glyphosate and its degradate AMPA to streams in the United States

Glyphosate is the most widely used herbicide in the world, being routinely applied to control weeds in both agricultural and urban settings. Microbial degradation of glyphosate produces aminomethyl phosphonic acid (AMPA). The high polarity and water-solubility of glyphosate and AMPA has, until recently, made their analysis in water samples problematic. Thus, compared to other herbicides (e.g. atrazine) there are relatively few studies on the environmental occurrence of glyphosate and AMPA. In 2002, treated effluent samples were collected from 10 wastewater treatment plants (WWTPs) to study the occurrence of glyphosate and AMPA. Stream samples were collected upstream and downstream of the 10 WWTPs. Two reference streams were also sampled. The results document the apparent contribution of WWTP effluent to stream concentrations of glyphosate and AMPA, with roughly a two-fold increase in their frequencies of detection between stream samples collected upstream and those collected downstream of the WWTPs. Thus, urban use of glyphosate contributes to glyphosate and AMPA concentrations in streams in the United States. Overall, AMPA was detected much more frequently (67.5%) compared to glyphosate (17.5%).

Science of the Total Environment↗

USGS1996

Late Proterozoic and Paleozoic tides, retreat of the moon, and rotation of the earth

The tidal rhythmites in the Proterozoic Big Cottonwood Formation (Utah, United States), the Neoproterozoic Elatina Formation of the Flinders Range (southern Australia), and the Lower Pennsylvanian Pottsville Formation (Alabama, United States) and Mansfield Formation (Indiana, United States) indicate that the rate of retreat of the lunar orbit is d ξ/ dt ∼ k 2 sin(2δ) (where ξ is the Earth-moon radius vector, k 2 is the tidal Love number, and δ is the tidal lag angle) and that this rate has been approximately constant since the late Precambrian. When the contribution to tidal friction from the sun is taken into account, these data imply that the length of the terrestrial day 900 million years ago was ∼18 hours.

Alabama, Indiana, Utah↗

USGS2001

U.S. Geological Survey Information Sources

As the Nation's largest water, earth, and biological science and civilian mapping agency, the U.S. Geological Survey (USGS) works in cooperation with more than 2,000 organizations across the country to provide reliable, impartial scientific information to resource managers, planners, and other customers. This information is gathered in every State by USGS scientists to minimize the loss of life and property from natural disasters, to contribute to the conservation and the sound economic and physical development of the Nation's natural resources, and to enhance the quality of life by monitoring water, biological, energy, and mineral resources

Fact Sheet↗

USGS2011

Bibliography of literature pertaining to Long Valley Caldera and associated volcanic fields

On May 25-27, 1980, Long Valley caldera was rocked by four M=6 earthquakes that heralded the onset of a wave of seismic activity within the caldera which has continued through the present. Unrest has taken the form of seismic swarms, uplift of the resurgent dome, and areas of vegetation killed by increased CO2 emissions, all interpreted as resulting from magma injection into different levels beneath the caldera, as well as beneath Mammoth Mountain along the southwest rim of the caldera. Continuing economic development in the Mammoth Lakes area has swelled the local population, increasing the risk to people and property if an eruption were to occur. The U.S. Geological Survey (USGS) has been monitoring geophysical activity in the Long Valley area since the mid-1970s and continues to track the unrest in real time with a sophisticated network of geophysical sensors. Hazards information obtained by this monitoring is provided to local, State, and Federal officials and to the public through the Long Valley Observatory. The Long Valley area also was scientifically important before the onset of current unrest. Lying at the eastern foot of the Sierra Nevada, the deposits from this active volcanic system have provided fertile ground for research into Neogene tectonics, Quaternary geology and geomorphology, regional stratigraphy, and volcanology. In the early 1970s, intensive studies of the area began through the USGS Geothermal Investigations Program, owing to the presence of a large young silicic volcanic system. The paroxysmal eruption of Long Valley caldera about 760,000 years ago produced the Bishop Tuff and associated Bishop ash. The Bishop Tuff is a well-preserved ignimbrite deposit that has continued to provide new and developing insights into the dynamics of ignimbrite-forming eruptions. Another extremely important aspect of the Bishop Tuff is that it is the oldest known normally magnetized unit of the Brunhes Chron. Thus, the age of the Bishop Tuff is used to define the beginning of the Brunhes Chron and helps constrain the Brunhes-Matuyama boundary. The Bishop ash, which was dispersed as far east as Nebraska, Kansas, and Texas, provides an important tephrostratigraphic marker throughout the Western United States. The obsidian domes of both the Mono and Inyo Craters, which were produced by rhyolitic eruptions in the past 40,000 years, have been well studied, including extensive scientific drilling through the domes. Exploratory drilling to 3-km depth on the resurgent dome and subsequent instrumentation of the Long Valley Exploratory Well (LVEW) have led to a number of important new insights. Scientific drilling also has been done within the Casa Diablo geothermal field, which, aside from drilling, has been commercially developed and is currently feeding 40 MW of power into the Southern California Edison grid. Studies in all the above-mentioned volcanic fields have contributed to the extensive scientific literature published on the Long Valley region. Although most of this scientific literature has been published since 1970, a significant amount of historical literature extends backward to the late 1800s. The purpose of this bibliography is to compile references pertaining to the Long Valley region from all time periods and all Earth science fields into a single listing, thus providing an easily accessible guide to the published literature for current and future researchers.

Open-File Report↗

USGS2020

Memorial to Jack B. Epstein 1935-2020

Jack Burton Epstein, a career geologist with the U.S. Geological Survey (USGS) passed away in May 2020 at his home in Great Falls, Virginia. His career and contributions to the USGS spanned more than 60 years from his time as a summer field assistant while attending college, through 40 years as a research geologist, and more than 15 years as an emeritus scientist. Jack was born December 27, 1935 in Brooklyn, New York and attended CUNY- Brooklyn College where he received his Bachelor of Science degree in geology in 1956. He earned his Master of Science degree in 1958 from the University of Wyoming, and his doctorate degree in geology in 1970 from The Ohio State University. His master’s thesis was geologic mapping of the Fanny Peak quadrangle, Black Hills of Wyoming and South Dakota, and his Ph. D. dissertation focused on the geology of the Stroudsburg quadrangle and adjacent areas, Pennsylvania and New Jersey.

Geological Society of America Memorials↗

USGS2005

Viability of male gametes in common carp ( Cyprinus carpio ) along the Lower Colorado River from the Cibola National Wildlife Refuge (NWR), Havasu NWR, and Lake Mohave of Lake Mead National Recreation Area

To contribute to an investigation on possible endocrine impacts in three sites along the lower Colorado River in Arizona, especially in male fishes, this study addressed the null hypothesis that aquatic species in southern sites did not exhibit evidence of endocrine disruption as compared with those in nonimpacted sites. The results presented are intended to provide managers with science-based information and interpretations about the reproductive condition of biota in their habitat along the lower Colorado River to minimize any potential adverse effects to trust fish and wildlife resources and to identify water resources of acceptable quality. In particular, these data can inform decision making about wastewater discharges into the Colorado River that directly supplies water to Arizona refuges located along the river. These data are integral to the USFWS proposal entitled 'AZ - Endocrine Disruption in Razorback Sucker and Common Carp on National Wildlife Refuges along the Lower Colorado River' that was proposed to assess evidence of endocrine disruption in carp and razorback suckers downstream of Hoover Dam.

Open-File Report↗

USGS2014

Urban ecosystem services and decision making for a green Philadelphia

Traditional approaches to urban development often do not account for, or recognize, the role of ecosystem services and the benefits these services provide to the health and well-being of city residents. Without such accounting, urban ecosystem services are likely to be degraded over time, with negative consequences for the sustainability of cities and the well-being of their residents (Millennium Ecosystem Assessment, 2005; Hirsch, 2008). On May 23, 2013, the Spatial Integration Laboratory for Urban Systems (SILUS), a collaboration between the U.S. Geological Survey (USGS) Science and Decisions Center and the Wharton GIS Lab, convened a one-day symposium—Urban Ecosystem Services and Decision Making: A Green Philadelphia—at the University of Pennsylvania in Philadelphia, Pennsylvania, to examine the role of green infrastructure in the environmental, economic, and social well-being of cities. Cosponsored by the USGS and the Penn Institute for Urban Research (Penn IUR), the symposium brought together policymakers, practitioners, and researchers from a range of disciplines to advance a research agenda on the use of science in public decision making to inform investment in green infrastructure and ecosystem services in urban areas. The city of Philadelphia has recently implemented a program designed to sustain urban ecosystem services and advance the use of green infrastructure. In 2009, the Philadelphia Mayor’s Office of Sustainability launched its Greenworks plan, establishing a citywide sustainability strategy. Major contributions towards its goals are being implemented in coordination with the Philadelphia Water Department (PWD). The Green City, Clean Waters initiative, the city’s nationally recognized stormwater management plan, was signed into action with the U.S. Environmental Protection Agency (EPA) in April 2012. The plan outlines a 25-year strategy to use green infrastructure to protect and improve the city’s watershed. Widespread support for the plan marks a citywide effort to factor environmental quality concerns into the city’s strategic planning, choosing to replace expensive and aging grey infrastructure, with innovative and resilient green infrastructure. The symposium focused on these city of Philadelphia initiatives and also on two new Federal- local partnership programs: America’s Great Outdoors, initiated to promote conservation and recreation, and the Urban Waters Federal Partnership, a multiagency effort to reconnect urban communities to their waterways. A second goal of the symposium was to advance a research agenda on urban ecosystem services. While there has been considerable work on ecosystem services, the discussion of the benefits provided by urban ecosystems is not as developed. Benefits range from improved water and air quality to quality of life gains, including aesthetic and recreational considerations. There is also need for additional focused research toward furthering the understanding of the multiple indirect benefits provided by urban ecosystem services (Bolund and Hunhammar, 1999). Moreover, there is a need for a greater understanding of how best to inform local decision making in this area, as local decision makers in cities across the country are increasingly recognizing the importance of developing sustainability measures for their immediate and long-term planning (United States Conference of Mayors, 2005). Approaching these local and regional plans from a holistic perspective has become a guiding principle of sustainability and resiliency. Therefore, there is a need to better understand the gains that have been achieved and to advance a research agenda on ecosystem services going forward. The day’s program included presentations on greening initiatives from the Philadelphia’s Mayor’s Office of Sustainability, as well as discussion about using an urban ecosystem services framework to evaluate these initiatives. Panel sessions included discussion of the Green City, Clean Waters initiative; a dialogue about the management of urban trees and green space; and a conversation addressing the needs for future research.

Pennsylvania↗

USGS2001

Tampa Bay Integrated Science Pilot Study: Baseline mapping, land surface dynamics and predictive modeling, and hazards vulnerability studies

Tampa Bay and its environs have experienced phenomenal urban growth and significant changes in land cover and land-use practices over the past 50 years. This trend is expected to continue, with the impact of human activity broadening geographically and intensifying throughout the region. One of the immediate impacts of urban growth is the creation of additional impervious surfaces, which in turn, generate increased urban runoff that contributes to higher levels of nutrient loading in water bodies throughout the area. To better understand these and other anthropogenic affects on the ecology of the natural environment of the region, this component of the Tampa Bay Pilot Study took a broad basin-wide view. This regional view was intended to provide geographic and temporal context for the smaller intensely studied sample field site locations within the estuarine environment.

Open-File Report↗

USGS2009

Elevated CO 2 stimulates marsh elevation gain, counterbalancing sea-level rise

Tidal wetlands experiencing increased rates of sea-level rise (SLR) must increase rates of soil elevation gain to avoid permanent conversion to open water. The maximal rate of SLR that these ecosystems can tolerate depends partly on mineral sediment deposition, but the accumulation of organic matter is equally important for many wetlands. Plant productivity drives organic matter dynamics and is sensitive to global change factors, such as rising atmospheric CO 2 concentration. It remains unknown how global change will influence organic mechanisms that determine future tidal wetland viability. Here, we present experimental evidence that plant response to elevated atmospheric [CO 2 ] stimulates biogenic mechanisms of elevation gain in a brackish marsh. Elevated CO 2 (ambient + 340 ppm) accelerated soil elevation gain by 3.9 mm yr −1 in this 2-year field study, an effect mediated by stimulation of below-ground plant productivity. Further, a companion greenhouse experiment revealed that the CO 2 effect was enhanced under salinity and flooding conditions likely to accompany future SLR. Our results indicate that by stimulating biogenic contributions to marsh elevation, increases in the greenhouse gas, CO 2 , may paradoxically aid some coastal wetlands in counterbalancing rising seas.

Proceedings of the National Academy of Sciences↗

USGS2015

Fire effects on aquatic ecosystems: An assessment of the current state of the science

Fire is a prevalent feature of many landscapes and has numerous and complex effects on geological, hydrological, ecological, and economic systems. In some regions, the frequency and intensity of wildfire have increased in recent years and are projected to escalate with predicted climatic and landuse changes. In addition, prescribed burns continue to be used in many parts of the world to clear vegetation for development projects, encourage desired vegetation, and reduce fuel loads. Given the prevalence of fire on the landscape, authors of papers in this special series examine the complexities of fire as a disturbance shaping freshwater ecosystems and highlight the state of the science. These papers cover key aspects of fire effects that range from vegetation loss and recovery in watersheds to effects on hydrology and water quality with consequences for communities (from algae to fish), food webs, and ecosystem processes (e.g., organic matter subsidies, nutrient cycling) across a range of scales. The results presented in this special series of articles expand our knowledge of fire effects in different biomes, water bodies, and geographic regions, encompassing aquatic population, community, and ecosystem responses. In this overview, we summarize each paper and emphasize its contributions to knowledge on fire ecology and freshwater ecosystems. This overview concludes with a list of 7 research foci that are needed to further our knowledge of fire effects on aquatic ecosystems, including research on: 1) additional biomes and geographic regions; 2) additional habitats, including wetlands and lacustrine ecosystems; 3) different fire severities, sizes, and spatial configurations; and 4) additional response variables (e.g., ecosystem processes) 5) over long (>5 y) time scales 6) with more rigorous study designs and data analyses, and 7) consideration of the effects of fire management practices and policies on aquatic ecosystems.

Freshwater Science↗

USGS2026

Guidelines for producing integrated 210Pb and 14C age-models

Accurate reconstructions of past environmental changes are crucial in paleoecological research and require reliable chronologies of sedimentary archives. Establishing robust age-models and obtaining the most appropriate proxies for analysis is a complex scientific endeavor, requiring extensive resources and collaboration among specialists, including radiochronologists. Radiometric dating methods, such as 210 Pb and radiocarbon ( 14 C), are frequently employed to establish chronologies in aquatic sedimentary deposits and peat bogs. In this study, we review key aspects of sampling, analysis, and the principles underlying 210 Pb and 14 C age-models, focusing on methods for developing robust joint chronologies for paleoenvironmental research. Drawing largely from the authors' experiences and group discussions during and after a scientific workshop in 2022, we discuss important considerations for site selection, sampling strategies, and radiometric dating to construct integrated 210 Pb and 14 C age-models. Using expert consensus, this group – called Paleostats – aims to provide a set of best practices for other geochronologists with this methods paper. Among our conclusions, we emphasize the importance of accounting for site-specific factors such as prior information on sedimentation rates to establish appropriate sampling and analytical strategies. The use of appropriate coring devices can minimize disturbance to sediments and ensure the core surface remains intact and preserved until sectioning. Where excess 210 Pb is expected, sectioning at intervals of ≤1 cm provides an adequate sampling resolution for 210 Pb dating. Exceptions are possible, allowing for ~2–3 cm sections in areas with confirmed high sedimentation rates (e.g., > 1 cm yr −1 ). Recovering deeper core sections for 14 C dating with sufficient overlap allows for accounting errors in depth estimates made in the field. Special attention is advised during time intervals where validation proxies, such as the human-made radionuclides 137 Cs or post-bomb 14 C, are expected, and to determine the depth of secular equilibrium between 210 Pb and 226 Ra. Radiocarbon analyses are commonly performed by accelerator mass spectrometry, and age models are constructed mainly using Bayesian statistics with Markov Chain Monte Carlo techniques (e.g., Bacon ). A Bayesian approach ( Plum ) is now available for producing 210 Pb age-models, which infers the 210 Pb ex flux, eliminates the need for selecting an equilibrium depth, and allows dating cores with incomplete 210 Pb ex inventory. Plum offers improved chronologies by integrating raw 210 Pb and 14 C data, and these age-models can be enriched with other dating methodologies, such as identifying tephras and other well-recorded historical events. Harmonized reporting would contribute to making radiometric age-models reproducible, which would benefit from an international effort. Using 210 Pb and 14 C to produce integrated age-models may yield better insights into the interplay between natural and recent anthropogenic forcings on ecosystems. This can enhance our understanding of environmental processes and their impacts on climate change, ultimately supporting science-based assessments and decisions.

Earth-Science Reviews↗

USGS2001

Chemotaxonomy for naturally macerated tree-fern cuticles (Medullosales and Marattiales), Carboniferous Sydney and Mabou Sub-Basins, Nova Scotia, Canada

Naturally macerated cuticles (NMC) and one synangium, representing medullosalean and marattialean tree-fern species, from two Carboniferous coalfields in Nova Scotia, Canada, are investigated. The samples were analyzed by infrared spectroscopy (FTIR), and by pyrolysis-gas chromatograph/mass spectrometry (py-Gc/Ms) techniques in search for chemical signatures that would help in developing a chemotaxonomic classification of Carboniferous fern species, assuming genetically dependent make-up of cuticles. FTIR-derived CH2/CH3 ratios, in conjunction with contributions from carboxyl groups, demonstrated a better potential for discriminating between medullosalean genera and species than molecular signatures obtained by py-Gc/Ms. However, the latter provided better data for differentiating medullosalean from marattialean tree ferns as a group. Changes in the chemical make-up of naturally macerated cuticles due to sample preparation are discussed. ?? 2001 Elsevier Science B.V. All rights reserved.

International Journal of Coal Geology↗

USGS2011

USGS St. Petersburg Coastal and Marine Science Center

Extreme storms, sea-level rise, and the health of marine communities are some of the major societal and environmental issues impacting our Nation's marine and coastal realm. The U.S. Geological Survey (USGS) in St. Petersburg, Fla., investigates processes related to these ecosystems and the societal implications of natural hazards and resource sustainability. As one of three centers nationwide conducting research within the USGS Coastal and Marine Geology Program, the center is integral towards developing an understanding of physical processes that will contribute to rational decisions regarding the use and stewardship of national coastal and marine environments.

Florida↗

USGS2024

Seismicity zoning at Coso geothermal field and stress changes from fluid production and migration

The Coso geothermal field is a major geothermal power production site in the western United States. It has been observed that low-magnitude seismic events ( M < 3.71) are unevenly distributed in three distinct zones, namely, nearfield (<3 km), midfield (3–6 km), and farfield (> 6 km) from the Coso geothermal plant. These zones exhibit distinct changes in earthquake location before and during geothermal production episodes that began in 1986. After 1986, the midfield region of the main flank experiences a significantly lower seismicity rate than the surrounding areas before production episodes. During 2014–2019, the farfield earthquakes cluster in the eastern and western parts of the greater Coso area, which is discernably different from how those pre-production earthquake events were distributed along the conjugate NW-SE and SW-NW trending structures across the main flank. Here, we analyze the stage of stress with finite-element-based poroelastic simulations to illustrate how the spatiotemporal evolution of the seismicity is associated with the pattern of stress perturbations caused by fluid migration amid the operations of geothermal power plants. Generally, ∼70% of co-production seismicity is found in zones of increased Coulomb stress between 2014 and 2019 at >99% confidence. Meanwhile, the midfield zone of seismic paucity overlaps with the zone of decreasing pore-fluid pressure. Overall, the results provide a physical explanation of how decadal geothermal operations at Coso have perturbed stress-field changes and contributed to the evolving characteristic seismic pattern, shedding insights into assessing the seismic hazard in other geothermal settings.

California↗

USGS2016

Plastic debris in 29 Great Lakes tributaries: Relations to watershed attributes and hydrology

Plastic debris is a growing contaminant of concern in freshwater environments, yet sources, transport, and fate remain unclear. This study characterized the quantity and morphology of floating micro- and macroplastics in 29 Great Lakes tributaries in six states under different land covers, wastewater effluent contributions, population densities, and hydrologic conditions. Tributaries were sampled three or four times each using a 333 μm mesh neuston net. Plastic particles were sorted by size, counted, and categorized as fibers/lines, pellets/beads, foams, films, and fragments. Plastics were found in all 107 samples, with a maximum concentration of 32 particles/m 3 and a median of 1.9 particles/m 3 . Ninety-eight percent of sampled plastic particles were less than 4.75 mm in diameter and therefore considered microplastics. Fragments, films, foams, and pellets/beads were positively correlated with urban-related watershed attributes and were found at greater concentrations during runoff-event conditions. Fibers, the most frequently detected particle type, were not associated with urban-related watershed attributes, wastewater effluent contribution, or hydrologic condition. Results from this study add to the body of information currently available on microplastics in different environmental compartments, including unique contributions to quantify their occurrence and variability in rivers with a wide variety of different land-use characteristics while highlighting differences between surface samples from rivers compared with lakes.

Environmental Science & Technology↗

USGS2020

The influence of climate variability on the accuracy of NHD perennial and non-perennial stream classifications

National Hydrography Dataset (NHD) stream permanence classifications (SPC; perennial, intermittent, and ephemeral) are widely used for data visualization and applied science, and have implications for resource policy and management. NHD SPC were assigned using a combination of topographic field surveys and interviews with local residents. However, previous studies indicate that non‐NHD, in situ streamflow observations (NNO) frequently disagree with NHD SPC. We hypothesized that differences in annual climate conditions between map creation years and the years NNO were collected contributed to disagreement between NNO and NHD SPC. We compared NHD SPC to 10,055 NNO (classified as “wet” or “dry”) collected in the Pacific Northwest between 1977 and 2015. Annual climate conditions were described with the Palmer Drought Severity Index (PDSI). Stream order was added as a covariate to account for different effects along the stream network. NHD SPC agreed with 80.5% of NNO. “Dry” NNO were five times more likely to disagree with NHD than “wet” NNO ( p < 0.0001). Disagreement was greatest on first‐order streams. When NHD SPC were collected during a wetter period than NNO the probability of disagreement increased by a factor of 1.17 ( p < 0.0001) per unit difference in PDSI. The influence of climate on disagreements between NNO and NHD SPC provides support for the continued development of dynamic models representing SPC as opposed to static NHD classifications.

Journal of the American Water Resources Associatio↗