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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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At least 253 records · Page 14Linked to original sources
USGS2014

Estimates of annual survival, growth, and recruitment of a white-tailed ptarmigan population in Colorado over 43 years

Long-term datasets for high-elevation species are rare, and considerable uncertainty exists in understanding how high-elevation populations have responded to recent climate warming. We present estimates of demographic vital rates from a 43-year population study of white-tailed ptarmigan ( Lagopus leucura ), a species endemic to alpine habitats in western North America. We used capture-recapture models to estimate annual rates of apparent survival, population growth, and recruitment for breeding-age ptarmigan, and we fit winter weather covariates to models in an attempt to explain annual variation. There were no trends in survival over the study period but there was strong support for age and sex effects. The average rate of annual growth suggests a relatively stable breeding-age population ( λ ¯ "> λ ¯ = 1.036), but there was considerable variation between years for both population growth and recruitment rates. Winter weather covariates only explained a small amount of variation in female survival and were not an important predictor of male survival. Cumulative winter precipitation was found to have a quadratic effect on female survival, with survival being highest during years of average precipitation. Cumulative winter precipitation was positively correlated with population growth and recruitment rates, although this covariate only explained a small amount of annual variation in these rates and there was considerable uncertainty among the models tested. Our results provide evidence for an alpine-endemic population that has not experienced extirpation or drastic declines. However, more information is needed to understand risks and vulnerabilities of warming effects on juveniles as our analysis was confined to determination of vital rates for breeding-age birds.

Colorado↗
USGS2005

Environmental exposure modeling and monitoring of human pharmaceutical concentrations in the environment

Human pharmaceuticals are receiving increased attention as environmental contaminants. This is due to their biological activity and the number of monitoring programs focusing on analysis of these compounds in various environmental media and compartments. Risk assessments are needed to understand the implications of reported concentrations; a fundamental part of the risk assessment is an assessment of environmental exposures. The purpose of this chapter is to provide guidance on the use of predictive tools (e.g., models) and monitoring data in exposure assessments for pharmaceuticals in the environment. Methods to predict environmental concentrations from equations based on first principles are presented. These equations form the basis of existing GIS (geographic information systems)-based systems for understanding the spatial distribution of pharmaceuticals in the environment. The pharmaceutical assessment and transport (P h ATE), georeferenced regional exposure assessment tool for European rivers (GREAT-ER), and geographical information system (GIS)-ROUT models are reviewed and recommendations are provided concerning the design and execution of monitoring studies. Model predictions and monitoring data are compared to evaluate the relative utility of each approach in environmental exposure assessments. In summary, both models and monitoring data can be used to define representative exposure concentrations of pharmaceuticals in the environment in support of environmental risk assessments.

Book chapter↗
USGS2021

Near-real-time volcanic cloud monitoring: Insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

Understanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a ) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

Bulletin of Volcanology↗
USGS2017

Identification of two novel reassortant avian influenza a (H5N6) viruses in whooper swans in Korea, 2016

Background On November 20, 2016 two novel strains of H5N6 highly pathogenic avian influenza virus (HPAIVs) were isolated from three whooper swans ( Cygnus cygnus ) at Gangjin Bay in South Jeolla province, South Korea. Identification of HPAIVs in wild birds is significant as there is a potential risk of transmission of these viruses to poultry and humans. Results Phylogenetic analysis revealed that Gangjin H5N6 viruses classified into Asian H5 clade 2.3.4.4 lineage and were distinguishable from H5N8 and H5N1 HPAIVs previously isolated in Korea. With the exception of the polymerase acidic (PA) gene, the viruses were most closely related to A/duck/Guangdong/01.01SZSGXJK005-Y/2016 (H5N6) (98.90 ~ 99.74%). The PA genes of the two novel Gangjin H5N6 viruses were most closely related to AIV isolates previously characterized from Korea, A/hooded crane/Korea/1176/2016 (H1N1) (99.16%) and A/environment/Korea/W133/2006 (H7N7) (98.65%). The lack of more recent viruses to A/environment/Korea/W133/2006 (H7N7) indicates the need for analysis of recent wild bird AIVs isolated in Korea because they might provide further clues as to the origin of these novel reassortant H5N6 viruses. Conclusions Although research on the origins and epidemiology of these infections is ongoing, the most likely route of infection for the whooper swans was through direct or indirect contact with reassortant viruses shed by migratory wild birds in Korea. As H5N6 HPAIVs can potentially be transmitted to poultry and humans, continuous monitoring of AIVs among wild birds will help to mitigate this risk.

Virology Journal↗
USGS2012

Using structured decision making to manage disease risk for Montana wildlife

We used structured decision-making to develop a 2-part framework to assist managers in the proactive management of disease outbreaks in Montana, USA. The first part of the framework is a model to estimate the probability of disease outbreak given field observations available to managers. The second part of the framework is decision analysis that evaluates likely outcomes of management alternatives based on the estimated probability of disease outbreak, and applies managers' values for different objectives to indicate a preferred management strategy. We used pneumonia in bighorn sheep (Ovis canadensis) as a case study for our approach, applying it to 2 populations in Montana that differed in their likelihood of a pneumonia outbreak. The framework provided credible predictions of both probability of disease outbreaks, as well as biological and monetary consequences of management actions. The structured decision-making approach to this problem was valuable for defining the challenges of disease management in a decentralized agency where decisions are generally made at the local level in cooperation with stakeholders. Our approach provides local managers with the ability to tailor management planning for disease outbreaks to local conditions. Further work is needed to refine our disease risk models and decision analysis, including robust prediction of disease outbreaks and improved assessment of management alternatives.

Montana↗
USGS2019

Short-term effects of ambient air pollution and cardiovascular events in Shiraz, Iran, 2009 to 2015

Air pollution and dust storms are associated with increased cardiovascular hospital admissions. The aim of this study was to investigate the association between short-term exposure to ambient air pollutants and CVD (cardiovascular disease) events in a long-term observational period. The study included the events of cardiovascular diseases (namely coronary artery disease, ischemic heart disease, myocardial infarction, and pneumo thrombo embolism) within the population of Shiraz, from March 21, 2009 to March 20, 2015. Also, each patient’s demographics were recorded. Main meteorological variables and five ambient pollutants (CO, O 3 , SO 2 , NO 2 , and PM 10 ) were recorded. Statistical analysis was performed using linear regression (GLM) and a generalized additive model (GAM) estimating Poisson distribution and adjusted for the main risk factors and ambient meteorological variables. A mild prevalence (51.5%) of coronary artery disease (CAD) was registered in 6425 events. In GLM analysis, we observed an association among the pollutants with the coronary artery disease hospital admissions which was in the order of CO, NO 2 , and PM 10 . The highest association of each pollutant with hospital admission was observed as PM 10 at lag 4 (RR = 1.08; 95% CI 1.02, 1.14 and p < 0.05), NO 2 at lag 0 (RR = 1.22; 95% CI 1.00, 1.48), and CO at lag 0 (RR = 1.52 95% CI = (1.16, 1.99)). However, on dusty days, there were significantly higher numbers of referrals of cardiovascular patients (mean = 7.54 ± 4.44 and p = 0.002,) than on non-dusty days. According to these data, dust storms and some types of pollutants in the air are responsible for more admissions to hospitals for cardiovascular problems.

Shiraz↗
USGS2012

Uncertainty

Management decisions will often be directly informed by model predictions. However, we now know there can be no expectation of a single ‘true’ model; thus, model results are uncertain. Understandable reporting of underlying uncertainty provides necessary context to decision-makers, as model results are used for management decisions. This, in turn, forms a mechanism by which groundwater models inform a risk-management framework because uncertainty around a prediction provides the basis for estimating the probability or likelihood of some event occurring. Given that the consequences of management decisions vary, it follows that the extent of and resources devoted to an uncertainty analysis may depend on the consequences. For events with low impact, a qualitative, limited uncertainty analysis may be sufficient for informing a decision. For events with a high impact, on the other hand, the risks might be better assessed and associated decisions made using a more robust and comprehensive uncertainty analysis. The purpose of this chapter is to provide guidance on uncertainty analysis through discussion of concepts and approaches, which can vary from heuristic (i.e. the modeller’s assessment of prediction uncertainty based on trial and error and experience) to a comprehensive, sophisticated, statistics-based uncertainty analysis. Most of the material presented here is taken from Doherty et al. (2010) if not otherwise cited. Although the treatment here is necessarily brief, the reader can find citations for the source material and additional references within this chapter.

Book chapter↗
USGS2025

Preface to the focus section on earthquake-induced ground deformation

Ground failure due to earthquake-induced liquefaction, surface fault rupture, and landsliding has caused substantial damage in the past and continues to pose risks to critical infrastructure in the future. The consideration of ground failure is central to engineering analysis and design, ranging from site-specific engineering assessments of ground failure potential to broader regional-scale ground failure assessments of near-real-time earthquake impacts or longer-term portfolio risk. Uncertainties in all aspects of the problem complicate the prediction of earthquake-induced ground failure, including the identification of hazard-susceptible geomaterials, characterizing their spatial extent and physical properties, spatio-temporal variability in groundwater conditions, characterization of earthquake ground motions, assessing ground failure severity, and linking ground failure severity to infrastructure damage and loss.

Seismological Research Letters↗
USGS2023

Modeling groundwater-level responses to multiple stresses using transfer-function models and wavelet analysis in a coastal aquifer system

In coastal aquifers, dynamic stresses such as climate forcings, groundwater withdrawals, and ocean tidal fluctuations cause nonlinear responses to groundwater levels. Such responses to the stresses impact groundwater resources and related flooding and infrastructure risks at multiple scales. We used time-series models such as transfer-function models and wavelet analysis to quantify the relative contribution of these stresses to groundwater-level fluctuation in wells from the unconfined and confined aquifers in an Atlantic coastal aquifer. Climate forcings, such as precipitation and temperature, explained most of the groundwater-level variation for wells in the unconfined aquifer, whereas groundwater withdrawals were the dominant driver of groundwater levels for wells in the confined aquifer. The impact of groundwater withdrawals also was detected in several wells in the unconfined aquifer. Although the influence of ocean tides on groundwater levels commonly is observed in coastal aquifers, we found that daily groundwater withdrawals can obscure the semi-diurnal coherence signal of the two series. The magnitude of groundwater-level fluctuation that could be explained solely by tides was minor compared to that explained by climate or withdrawal stresses. Transfer-function modeling showed seasonal withdrawals from wells in confined aquifers had a significant, yet heterogeneous influence on groundwater levels in coastal aquifers, which highlights climate and withdrawals as key compounding stresses in coastal hydrology. This study demonstrates the value of time-series approaches to advance characterization of groundwater systems in areas with limited hydrogeologic parameter information.

Virginia↗
USGS2001

Constructing event trees for volcanic crises

Event trees are useful frameworks for discussing probabilities of possible outcomes of volcanic unrest. Each branch of the tree leads from a necessary prior event to a more specific outcome, e.g., from an eruption to a pyroclastic flow. Where volcanic processes are poorly understood, probability estimates might be purely empirical - utilizing observations of past and current activity and an assumption that the future will mimic the past or follow a present trend. If processes are better understood, probabilities might be estimated from a theoritical model, either subjectively or by numerical simulations. Use of Bayes' theorem aids in the estimation of how fresh unrest raises (or lowers) the probabilities of eruptions. Use of event trees during volcanic crises can help volcanologists to critically review their analysis of hazard, and help officials and individuals to compare volcanic risks with more familiar risks. Trees also emphasize the inherently probabilistic nature of volcano forecasts, with multiple possible outcomes.

Bulletin of Volcanology↗
USGS2017

Unconventional oil and gas spills: Risks, mitigation priorities, and state reporting requirements

Rapid growth in unconventional oil and gas (UOG) has produced jobs, revenue, and energy, but also concerns over spills and environmental risks. We assessed spill data from 2005 to 2014 at 31 481 UOG wells in Colorado, New Mexico, North Dakota, and Pennsylvania. We found 2–16% of wells reported a spill each year. Median spill volumes ranged from 0.5 m 3 in Pennsylvania to 4.9 m 3 in New Mexico; the largest spills exceeded 100 m 3 . Seventy-five to 94% of spills occurred within the first three years of well life when wells were drilled, completed, and had their largest production volumes. Across all four states, 50% of spills were related to storage and moving fluids via flowlines. Reporting rates varied by state, affecting spill rates and requiring extensive time and effort getting data into a usable format. Enhanced and standardized regulatory requirements for reporting spills could improve the accuracy and speed of analyses to identify and prevent spill risks and mitigate potential environmental damage. Transparency for data sharing and analysis will be increasingly important as UOG development expands. We designed an interactive spills data visualization tool ( http://snappartnership.net/groups/hydraulic-fracturing/webapp/spills.html ) to illustrate the value of having standardized, public data.

Environmental Science & Technology↗
USGS2022

A global ensemble of ocean wave climate statistics from contemporary wave reanalysis and hindcasts

There are numerous global ocean wave reanalysis and hindcast products currently being distributed and used across different scientific fields. However, there is not a consistent dataset that can sample across all existing products based on a standardized framework. Here, we present and describe the first coordinated multi-product ensemble of present-day global wave fields available to date. This dataset, produced through the Coordinated Ocean Wave Climate Project (COWCLIP) phase 2, includes general and extreme statistics of significant wave height ( H s ), mean wave period ( T m ) and mean wave direction ( θ m ) computed across 1980–2014, at different frequency resolutions (monthly, seasonally, and annually). This coordinated global ensemble has been derived from fourteen state-of-the-science global wave products obtained from different atmospheric reanalysis forcing and downscaling methods. This data set has been processed, under a specific framework for consistency and quality, following standard Data Reference Syntax, Directory Structures and Metadata specifications. This new comprehensive dataset provides support to future broad-scale analysis of historical wave climatology and variability as well as coastal risk and vulnerability assessments across offshore and coastal engineering applications.

Scientific Data↗
USGS2020

Batrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians

The salamander chytrid fungus (Batrachochytrium salamandrivorans [Bsal]) is causing massive mortality of salamanders in Europe. The potential for spread via international trade into North America and the high diversity of salamanders has catalyzed concern about Bsal in the U.S. Surveillance programs for invading pathogens must initially meet challenges that include low rates of occurrence on the landscape, low prevalence at a site, and imperfect detection of the diagnostic tests. We implemented a large-scale survey to determine if Bsal was present in North America designed to target taxa and localities where Bsal was determined highest risk to be present based on species susceptibility and geography. Our analysis included a Bayesian model to estimate the probability of occurrence of Bsal given our prior knowledge of the occurrence and prevalence of the pathogen. We failed to detect Bsal in any of 11,189 samples from 594 sites in 223 counties within 35 U.S. states and one site in Mexico. Our modeling indicates that Bsal is highly unlikely to occur within wild amphibians in the U.S. and suggests that the best proactive response is to continue mitigation efforts against the introduction and establishment of the disease and to develop plans to reduce impacts should Bsal establish.

Continental United States↗
USGS2013

Is exposure to cyanobacteria an environmental risk factor for amyotrophic lateral sclerosis and other neurodegenerative diseases?

There is a broad scientific consensus that amyotrophic lateral sclerosis (ALS) is caused by gene-environment interactions. Mutations in genes underlying familial ALS (fALS) have been discovered in only 5–10% of the total population of ALS patients. Relatively little attention has been paid to environmental and lifestyle factors that may trigger the cascade of motor neuron death leading to the syndrome of ALS, although exposure to chemicals including lead and pesticides, and to agricultural environments, smoking, certain sports, and trauma have all been identified with an increased risk of ALS. There is a need for research to quantify the relative roles of each of the identified risk factors for ALS. Recent evidence has strengthened the theory that chronic environmental exposure to the neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) produced by cyanobacteria may be an environmental risk factor for ALS. Here we describe methods that may be used to assess exposure to cyanobacteria, and hence potentially to BMAA, namely an epidemiologic questionnaire and direct and indirect methods for estimating the cyanobacterial load in ecosystems. Rigorous epidemiologic studies could determine the risks associated with exposure to cyanobacteria, and if combined with genetic analysis of ALS cases and controls could reveal etiologically important gene-environment interactions in genetically vulnerable individuals.

Amyotrophic Lateral Sclerosis and Frontotemporal D↗
USGS1995

Origin of water that discharges from Calf Creek Spring, Garfield County, Utah

Calf Creek Spring provides drinking water to users of Calf Creek Campground, which is operated by the Bureau of Land Management in southcentral Utah. Use of all methods and tools available indicates that surface water from Calf Creek does not contribute to the discharge of Calf Creek Spring. Microscopic Particulate Analysis of spring water indicates that the spring has a low risk of surface-water contamination, which is substantiated by a bacterial test of water from the point of discharge of Calf Creek Spring, the Calf Creek Spring collection box, a tap from the water distribution system, and Calf Creek near the picnic area. Bacteria colonies were found in Calf Creek near the picnic area. Calf Creek Spring discharges from fractured Navajo Sandstone where the potential for contamination by animal or human microbes is slight. Calf Creek probably gains water along its entire length from the aquifer in the Navajo Sandstone. Once at the surface, water in Calf Creek is exposed to animal- and human-borne microbes. If the water level in the Navajo aquifer at the spring remains higher than the water level of the creek, mixing is unlikely to occur and contamination is unlikely. The water level of Calf Creek Spring in June 1994 was at least 4 feet above the water level of Calf Creek. Water from Calf Creek Spring is a mixed type composed of magnesium, calcium, sodium, bicarbonate, and sulfate ions, and water from Calf Creek is a mixed type composed of calcium, magnesium, bicarbonate, sulfate, and chloride ions. Compositional similarity is not unusual if both water sources are derived from the Navajo aquifer. Discharge and temperature measurements at the spring and in the creek in May and June 1994 vary independently and do not indicate a hydraulic connection. Turbidity measurements, though not conclusive, indicate that no direct hydraulic connection exists between Calf Creek and Calf Creek Spring. Hydrologic characteristics of Calf Creek provide evidence that the probable long-term, sustainable source of water is the Navajo aquifer and not precipitation-derived runoff. Ground-water leakage from adjacent drainages could contribute to perennial flow in Calf Creek. Fractures modify the movement of ground water to discharge areas, such as Calf Creek Spring.

Utah↗
USGS2023

Long-term demographic analysis of the Cape Sable seaside sparrow (1992–2021)

The Cape Sable seaside sparrow (Ammospiza maritima mirabilis) is an endangered species that has experienced a population decline of more than 60% since 1981. Despite its critical population status, a statistically robust analysis of the species’ demographic rates utilizing all data has yet to be completed (Benscoter et al. 2021). Furthermore, long-term population processes in response to hydrologic and environmental conditions have not been evaluated for this species. To address these substantial gaps in knowledge, 30 years of demographic data were synthesized to assess population dynamics of this imperiled species using an integrated population model (IPM). Three demographic data types (range-wide counts, capture-mark-recapture, nest monitoring) were incorporated into a unified IPM to evaluate demographic processes and predict population trajectories. The following were calculated: (1) annual estimates of annual population size, survival, and fecundity; (2) coefficient estimates of hydrologic and environmental variables on survival and fecundity; (3) estimates of annual population growth and their correlation with demographic rates; and (4) a Bayesian population viability analysis (BPVA) that includes predicted population size, demographic rates, and extinction risks ten years into the future.

Report↗
USGS2022

Dynamic material flow analysis of tantalum in the United States from 2002 to 2020

Tantalum has received considerable attention due to risks associated with its supply chain. In 2020 ∼70% of global tantalum supply originated in Africa, with 40% produced in the Democratic Republic of Congo alone. The United States has relied entirely on imports since the 1950s. However, quantifying total domestic consumption is problematic because refined tantalum compounds do not have unique tariff codes resulting in significant trade volumes not properly documented. Furthermore, tantalum incorporated into finished goods is not tracked as tantalum. Thus, estimates only capture a fraction of total consumption. We performed a material flow analysis to quantify total domestic tantalum consumption from 2002 to 2020. Our results indicate that consumption may be up to 250% more than previously estimated. Our detailed results allow quantification of tantalum stocks in-use as well as coming out of use any year, providing valuable insight to industry and policymakers for addressing potential supply security issues.

Resources, Conservation & Recycling↗
USGS2025

Framework for assessing intranational risk of critical mineral sectors: Case study of India

Recent geopolitical actions regarding the supply of critical minerals have highlighted both the threats posed by countries dominating a critical mineral supply chain, and the potential mitigations served by alternative supplier countries. However, no systematic quantification exists for the intranational factors that determine such threats or mitigations. This study outlines a methodological framework for quantifying the intranational risk profile of critical mineral sectors and compares them with the sector's international potential for leverage. The four intranational factors of concentration, synchronization, private sector involvement, and regulatory obstacles were analyzed across multiple scales in order to determine an intranational risk score that quantifies the resilience or fragility of the critical mineral sector in question. Network analysis was also separately conducted to identify the most important entities operating across all critical mineral sectors. Finally, this study assessed the critical mineral sector's global share of reserves and production to determine an international risk score that quantifies the country's critical mineral sector's leverage potential. A case study of India showed that two critical mineral sectors with high leverage potential, chromite and barite, were respectively intranationally resilient and fragile. Of the remaining sectors with minimal leverage, five sectors such as aluminum were intranationally resilient and may serve as viable mitigation options for future critical mineral supply. Three sectors such as titanium were intranationally fragile, but recent regulatory developments may both decrease intranational risk and increase international risk, potentially making them major critical mineral sectors in the future.

Resources Policy↗