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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 415 records · Page 23Linked to original sources

USGS2001

Modeling Klamath River system operations for quantity and quality

Alternative water management scenarios for a portion of the mainstem Klamath River from Keno, Oregon, to Seiad Valley, California, were evaluated using computer models of water quantity (MODSIM) and quality (HEC-5Q). These models were used to explore the potential for changing system operations to improve summer/fall water quality conditions to benefit declining anadromous fish populations such as steelhead, coho, and fall chinook salmon. By comparing and contrasting several model simulation results, some operational strategies that could improve water quality were determined. Most of the alternatives evaluated decreased water temperature less than 2°C. For some alternatives, dissolved oxygen could be changed as much as 5 mg/L, but was often reduced, rather than increased (or improved). Resource managers need to be made aware that implementation of any strategy to enhance water quality conditions in the Klamath River could produce desirable beneficial results that are both spatially and temporally limited. In addition, undesirable water quality conditions, i.e., higher water temperature or lower dissolved oxygen concentration at other upstream or downstream locations, may also result.

California, Oregon↗

USGS2021

Ecogeographic variation and taxonomic boundaries in Large Treeshrews (Scandentia, Tupaiidae: Tupaia tana Raffles, 1821) from Southeast Asia

The Large Treeshrew, Tupaia tana Raffles, 1821, is a small mammal (~205 g) from Southeast Asia with a complicated taxonomic history. Currently, 15 subspecies are recognized from Borneo, Sumatra, and smaller islands, and many were originally differentiated based on minor pelage differences and small sample sizes. We explored intraspecific variation in T. tana using quantitative osteological data obtained from the hands and skulls of museum specimens. Multivariate analyses reveal extensive overlap among T. tana populations in morphospace, indicating that the majority of currently recognized subspecies are not morphometrically distinct. In contrast, the separation between Bornean and Sumatran populations of T. tana is sufficient to recognize them as different subspecies. Comparisons of Bornean specimens to those on small, offshore islands reveal that the latter average smaller body size. This pattern is inconsistent with Foster’s island rule, which predicts that island populations of small mammals (< 5 kg) will average larger body size relative to mainland forms. A similar lack of support for ecogeographic rules has been noted in T. glis (Diard, 1820), suggesting that these “rules” are poor predictors of geographic variation in treeshrews.

Journal of Mammalogy↗

USGS2021

The relevance of a type locality: The case of Mephitis interrupta Rafinesque, 1820 (Carnivora: Mephitidae)

For more than 130 years, the type locality of the Plains Spotted Skunk, Spilogale putorius interrupta (Rafinesque, 1820) has been accepted to be along the upper Missouri River. The species’ description was based on a specimen observed by Constantine S. Rafinesque during his 1818 exploration of the Ohio River Valley, but Rafinesque never ventured into the animal’s geographic range west of the Mississippi River, calling into question the type locality and, therefore, the identity of the taxon. We reconstruct Rafinesque’s itinerary from his notes, publications, and correspondence and determine that Rafinesque probably observed the specimen on 20 September in Middletown, Kentucky, while traveling between Louisville and Lexington. He spent the day with John Bradbury, who participated in the 1811 Astor expedition up the Missouri River. On 1 April 1811, Bradbury collected the skin of a skunk, and evidence suggests that it was this skin that Rafinesque described. The type specimen of the Plains Spotted Skunk was obtained on the Missouri River flood plain in southern Chariton County or northern Saline County, Missouri, and this area should be considered the type locality for M. interrupta .

Illinois, Indiana, Kentucky, Missouri, New York, O↗

USGS2016

Uncertainty in tsunami sediment transport modeling

Erosion and deposition from tsunamis record information about tsunami hydrodynamics and size that can be interpreted to improve tsunami hazard assessment. We explore sources and methods for quantifying uncertainty in tsunami sediment transport modeling. Uncertainty varies with tsunami, study site, available input data, sediment grain size, and model. Although uncertainty has the potential to be large, published case studies indicate that both forward and inverse tsunami sediment transport models perform well enough to be useful for deciphering tsunami characteristics, including size, from deposits. New techniques for quantifying uncertainty, such as Ensemble Kalman Filtering inversion, and more rigorous reporting of uncertainties will advance the science of tsunami sediment transport modeling. Uncertainty may be decreased with additional laboratory studies that increase our understanding of the semi-empirical parameters and physics of tsunami sediment transport, standardized benchmark tests to assess model performance, and development of hybrid modeling approaches to exploit the strengths of forward and inverse models.

Journal of Disaster Research↗

USGS2008

Exploring visitor acceptability for hardening trails to sustain visitation and minimize impacts

Protected natural area managers are challenged to provide high quality recreation opportunities and ensure the protection of resources from impacts associated with visitation. Development of visitor use facilities and application of site hardening practices are commonly applied tools for achieving these competing management objectives. This study applies stated choice analysis to examine visitor opinions on acceptability when they are asked to make tradeoffs among competing social, resource and management attributes in backcountry and frontcountry settings of Acadia National Park. This study demonstrates that asking visitors about recreation setting attributes uni-dimensionally, a common approach, can yield less informative responses. Analyses that considered direct tradeoffs revealed more divergent opinions on acceptability for setting attributes than a unidimensional approach. Findings revealed that visitors to an accessible and popular attraction feature supported trail development options to protect resource conditions with unrestricted visitor access. In contrast, visitors to a remote undeveloped island expressed stronger support for no or limited trail development and access restrictions to protect resource conditions.

Journal of Sustainable Tourism↗

USGS2023

A web-based application for exploring potential changes in design peak flow of U.S. urban areas driven by land cover change

Floods have become increasingly prominent in recent decades, especially in urban areas causing devastating effects on lives and livelihoods worldwide. Efficient tools to assess the drivers of floods, such as increasing urbanization could help to minimize flood hazards. A Google Earth Engine (GEE) application was developed to explore the potential changes (1985-2020) in design peak-flow of urban areas across the conterminous United States driven by land cover change. The results indicate a potential increase in peak-flow in urban areas up to 126.6% in 2020 compared to 1985. Out of the total 3535 study urban areas, about 80% (2840) urban areas increased peak-flow and about 19% (654) decreased peak-flow. A general pattern of increasing peak-flow was observed during 1985-2010 and decreasing pattern during 2010-2020, primarily driven by respective increasing (decreasing) and decreasing (increasing) developed areas (croplands). The GEE application pro-vides crucial information by visualizing both spatial and temporal data that could be useful for decision-makers in developing and improving urban stormwater management plans and policies for efficient resource allocations and reducing flood risks.

Journal of Remote Sensing↗

USGS2006

Morphological and electrophysiological examination of olfactory sensory neurons during the early developmental prolarval stage of the sea lamprey Petromyzon marinus L

This study examined olfactory sensory neuron morphology and physiological responsiveness in newly hatched sea lamprey, Petromyzon marinus L. These prolarvae hatch shortly after neural tube formation, and stay within nests for approximately 18 days, before moving downstream to silty areas where they burrow, feed and pass to the larval stage. To explore the possibility that the olfactory system is functioning during this prolarval stage, morphological and physiological development of olfactory sensory neurons was examined. The nasal cavity contained an olfactory epithelium with ciliated olfactory sensory neurons. Axons formed aggregates in the basal portion of the olfactory epithelium and spanned the narrow distance between the olfactory epithelium and the brain. The presence of asymmetric synapses with agranular vesicles within fibers in the brain, adjacent to the olfactory epithelium suggests that there was synaptic connectivity between olfactory sensory axons and the brain. Neural recordings from the surface of the olfactory epithelium showed responses following the application of L-arginine, taurocholic acid, petromyzonol sulfate (a lamprey migratory pheromone), and water conditioned by conspecifics. These results suggest that lampreys may respond to olfactory sensory input during the prolarval stage. ?? 2006 Springer Science + Business Media, LLC.

Journal of Neurocytology↗

USGS2011

Characteristics, distribution, origin, and significance of opaline silica observed by the Spirit rover in Gusev crater, Mars

The presence of outcrops and soil (regolith) rich in opaline silica (∼65–92 wt % SiO 2 ) in association with volcanic materials adjacent to the “Home Plate” feature in Gusev crater is evidence for hydrothermal conditions. The Spirit rover has supplied a diverse set of observations that are used here to better understand the formation of silica and the activity, abundance, and fate of water in the first hydrothermal system to be explored in situ on Mars. We apply spectral, chemical, morphological, textural, and stratigraphic observations to assess whether the silica was produced by acid sulfate leaching of precursor rocks, by precipitation from silica‐rich solutions, or by some combination. The apparent lack of S enrichment and the relatively low oxidation state of the Home Plate silica‐rich materials appear inconsistent with the originally proposed Hawaiian analog for fumarolic acid sulfate leaching. The stratiform distribution of the silica‐rich outcrops and their porous and brecciated microtextures are consistent with sinter produced by silica precipitation. There is no evidence for crystalline quartz phases among the silica occurrences, an indication of the lack of diagenetic maturation following the production of the amorphous opaline phase.

Journal of Geophysical Research E: Planets↗

USGS2010

Sampling considerations for disease surveillance in wildlife populations

Disease surveillance in wildlife populations involves detecting the presence of a disease, characterizing its prevalence and spread, and subsequent monitoring. A probability sample of animals selected from the population and corresponding estimators of disease prevalence and detection provide estimates with quantifiable statistical properties, but this approach is rarely used. Although wildlife scientists often assume probability sampling and random disease distributions to calculate sample sizes, convenience samples (i.e., samples of readily available animals) are typically used, and disease distributions are rarely random. We demonstrate how landscape-based simulation can be used to explore properties of estimators from convenience samples in relation to probability samples. We used simulation methods to model what is known about the habitat preferences of the wildlife population, the disease distribution, and the potential biases of the convenience-sample approach. Using chronic wasting disease in free-ranging deer (Odocoileus virginianus) as a simple illustration, we show that using probability sample designs with appropriate estimators provides unbiased surveillance parameter estimates but that the selection bias and coverage errors associated with convenience samples can lead to biased and misleading results. We also suggest practical alternatives to convenience samples that mix probability and convenience sampling. For example, a sample of land areas can be selected using a probability design that oversamples areas with larger animal populations, followed by harvesting of individual animals within sampled areas using a convenience sampling method.

Journal of Wildlife Management↗

USGS1999

Climatic impact of glacial cycle polar motion: Coupled oscillations of ice sheet mass and rotation pole position

Precessional motion of Earth's rotation axis relative to its orbit is a well-known source of long-period climatic variation. It is less well appreciated that growth and decay of polar ice sheets perturb the symmetry of the global mass distribution enough that the geographic location of the rotation axis will change by at least 15 km and possibly as much as 100 km during a single glacial cycle. This motion of the pole will change the seasonal and latitudinal pattern of temperatures. We present calculations, based on a diurnal average energy balance, which compare the summer and winter temperature anomalies due to a 1° decrease in obliquity with those due to a 1° motion of the rotation pole toward Hudson Bay. Both effects result in peak temperature perturbations of about 1° Celsius. The obliquity change primarily influences the amplitude of the seasonal cycle, while the polar motion primarily changes the annual mean temperatures. The polar motion induced temperature anomaly is such that it will act as a powerful negative feedback on ice sheet growth. We also explore the evolution of the coupled system composed of ice sheet mass and pole position. Oscillatory solutions result from the conflicting constraints of rotational and thermal stability. A positive mass anomaly on an otherwise featureless Earth is in rotational equilibrium only at the poles or the equator. The two polar equilibria are rotationally unstable, and the equatorial equilibrium, though rotationally stable, is thermally unstable. We find that with a plausible choice for the strength of coupling between the thermal and rotational systems, relatively modest external forcing can produce significant response at periods of 10 4 –10 6 years, but it strongly attenuates polar motion at longer periods. We suggest that these coupled oscillations may contribute to the observed dominance of 100 kyr glacial cycles since the mid-Pleistocene and will tend to stabilize geographic patterns that are suitable to glaciations.

Journal of Geophysical Research B: Solid Earth↗

USGS2013

Reconciling resource utilization and resource selection functions

Summary: 1. Analyses based on utilization distributions (UDs) have been ubiquitous in animal space use studies, largely because they are computationally straightforward and relatively easy to employ. Conventional applications of resource utilization functions (RUFs) suggest that estimates of UDs can be used as response variables in a regression involving spatial covariates of interest. 2. It has been claimed that contemporary implementations of RUFs can yield inference about resource selection, although to our knowledge, an explicit connection has not been described. 3. We explore the relationships between RUFs and resource selection functions from a hueristic and simulation perspective. We investigate several sources of potential bias in the estimation of resource selection coefficients using RUFs (e.g. the spatial covariance modelling that is often used in RUF analyses). 4. Our findings illustrate that RUFs can, in fact, serve as approximations to RSFs and are capable of providing inference about resource selection, but only with some modification and under specific circumstances. 5. Using real telemetry data as an example, we provide guidance on which methods for estimating resource selection may be more appropriate and in which situations. In general, if telemetry data are assumed to arise as a point process, then RSF methods may be preferable to RUFs; however, modified RUFs may provide less biased parameter estimates when the data are subject to location error.

Journal of Animal Ecology↗

USGS2008

Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analysis

Determining the processes governing aqueous biogeochemistry in a wetland hydrologically linked to an underlying contaminated aquifer is challenging due to the complex exchange between the systems and their distinct responses to changes in precipitation, recharge, and biological activities. To evaluate temporal and spatial processes in the wetland-aquifer system, water samples were collected using cm-scale multi-chambered passive diffusion samplers (peepers) to span the wetland-aquifer interface over a period of 3 yr. Samples were analyzed for major cations and anions, methane, and a suite of organic acids resulting in a large dataset of over 8000 points, which was evaluated using multivariate statistics. Principal component analysis (PCA) was chosen with the purpose of exploring the sources of variation in the dataset to expose related variables and provide insight into the biogeochemical processes that control the water chemistry of the system. Factor scores computed from PCA were mapped by date and depth. Patterns observed suggest that (i) fermentation is the process controlling the greatest variability in the dataset and it peaks in May; (ii) iron and sulfate reduction were the dominant terminal electron-accepting processes in the system and were associated with fermentation but had more complex seasonal variability than fermentation; (iii) methanogenesis was also important and associated with bacterial utilization of minerals as a source of electron acceptors (e.g., barite BaSO 4 ); and (iv) seasonal hydrological patterns (wet and dry periods) control the availability of electron acceptors through the reoxidation of reduced iron-sulfur species enhancing iron and sulfate reduction.

Journal of Environmental Quality↗

USGS2018

Assessing the risk of diploid grass carp Ctenopharyngodon idella in the certified triploid supply chain in Ohio

Non-native grass carp (Ctenopharyngodon idella) have been stocked in the United States for vegetation control since the 1970s, and recent evidence suggests some natural reproduction in the Great Lakes basin. Despite all states and provinces bordering Lake Erie either banning grass carp or requiring imports of only sterile, U.S. Fish and Wildlife Service (USFWS)-certified triploids, the majority of grass carp captured and analyzed from Lake Erie are diploid, or reproductively viable. Potential sources of diploid grass carp include illegal importation, compromises in the USFWS-certified triploid shipments, migration from legal diploid states, or natural reproduction resulting from diploid stockings prior to the 1988 Ohio law requiring only certified triploids. The goal of this study was to explore the risk that diploid grass carp occur in the USFWS-certified triploid supply chain destined for Ohio. During 2015 and 2016, undercover Ohio Department of Natural Resources-Division of Wildlife law enforcement purchased 1200 grass carp from 16 distributors, and overnighted 80 dissected grass carp head and eyeball sample shipments (n = 15 fish per shipment) for ploidy analysis by flow cytometry. Standardized methods for both field and laboratory processing were established. No diploid grass carp were detected in these collections, indicating fidelity of the USFWS-certified triploid grass carp supply chain in Ohio. Thus, these shipments are not a likely source of diploid grass carp in Lake Erie. This study is the first large-scale evaluation of the potential for ecological risk from diploid grass carp occurrence in USFSW-certified shipments of triploids for national distribution.

Ohio↗

USGS2017

Was the Mw 7.5 1952 Kern County, California, earthquake induced (or triggered)?

Several recent studies have presented evidence that significant induced earthquakes occurred in a number of oil-producing regions during the early and mid-twentieth century related to either production or wastewater injection. We consider whether the 21 July 1952 M w 7.5 Kern County earthquake might have been induced by production in the Wheeler Ridge oil field. The mainshock, which was not preceded by any significant foreshocks, occurred 98 days after the initial production of oil in Eocene strata at depths reaching 3 km, within ~1 km of the White Wolf fault (WWF). Based on this spatial and temporal proximity, we explore a potential causal relationship between the earthquake and oil production. While production would have normally be expected to have reduced pore pressure, inhibiting failure on the WWF, we present an analytical model based on industry stratigraphic data and best estimates of parameters whereby an impermeable splay fault adjacent to the main WWF could plausibly have blocked direct pore pressure effects, allowing the poroelastic stress change associated with production to destabilize the WWF, promoting initial failure. This proof-of-concept model can also account for the 98-day delay between the onset of production and the earthquake. While the earthquake clearly released stored tectonic stress, any initial perturbation on or near a major fault system can trigger a larger rupture. Our proposed mechanism provides an explanation for why significant earthquakes are not commonly induced by production in proximity to major faults.

California↗

USGS2018

Modeling White Sucker (Catostomus commersonii) populations to assess commercial harvest influence on age structure

Commercial harvest of White Suckers Catostomus commersonii for bait in the American Lobster Homarus americanus industry is minimally regulated in Maine and there are concerns as to the influence of increasing harvest. We built a population model using parameters (i.e. age-specific mortality, age at maturity, and size-specific fecundity) from literature and field studies to investigate the theoretical effects of harvest mortality on age structure. Because stock-recruitment relations are poorly characterized for this species, we explored the influence of both Beverton-Holt and Ricker recruitment processes. Our base model closely resembled the empirical age structures reported from three unfished lakes in Maine, with four percent of fish in the modeled spawning run being age-10 or older. We assessed the additive effects of harvest mortality on age structure using the full range of possible mortalities. As expected, increased harvest mortality in the model resulted in a decline and disappearance of older age-classes such that few fish greater than age-10 remained in the population under a realistic harvest mortality scenario. This age-truncation was qualitatively comparable to data from aggregate age distributions reported from three commercially harvested lakes in Maine. Because the loss of older fish may compromise population viability, this model is a valuable guidance tool for managers to craft regulation of this growing fishery.

Maine↗

USGS2018

Accounting for surveyor effort in large-scale monitoring programs

Accounting for errors in wildlife surveys is necessary for reliable status assessments and quantification of uncertainty in estimates of population size. We apply a hierarchical log-linear Poisson regression model that accounts for multiple sources of variability in count data collected for the Integrated Waterbird Management and Monitoring Program during 2010–2014. In some large-scale monitoring programs (e.g., Christmas Bird Count) there are diminishing returns in numbers counted as survey effort increases; therefore, we also explore the need to account for variable survey duration as a proxy for effort. In general, we found a high degree of concordance between counts and effort-adjusted estimates of relative abundance from the Integrated Waterbird Management and Monitoring Program ( x̄ difference = 0.02%; 0.25% SD). We suggest that the model-based adjustments were small because there is only a weak asymptotic relationship with effort and count. Whereas effort adjustments are reasonable and effective when applied to count data from plots of standardized area, such adjustments may not be necessary when the area of sample units is not standardized and surveyor effort increases with number of birds present. That is, large units require more effort only when there are many birds present. The general framework we implemented to evaluate effects of varying survey effort applies to a wide variety of wildlife monitoring efforts.

Journal of Fish and Wildlife Management↗

USGS2025

Exploring the importance of metapopulation dynamics with population control strategies for invasive silver carp in the upper Mississippi River

Invasive bigheaded carps (Bighead Carp Hypophthalmichthys nobilis , Silver Carp Hypophthalmichthys molitrix , and their hybrids Hypophthalmichthys spp.) currently infest the Mississippi River Basin. Bigheaded carps can outcompete native species in invaded waters and can also transform the surrounding environment. Currently, resource managers seek to limit the population abundance of bigheaded carps and their range expansion into additional regions of the Upper Mississippi River (UMR) but lack a tool to evaluate different control strategies. Here, we present an application of a Silver Carp spatial population model in the UMR to fill this gap. We used the model to explore how simulated control strategies could affect Silver Carp metapopulation dynamics. More specifically, we assessed and compared the importance of movement deterrents, removal locations, and recruitment areas on Silver Carp population abundances across the UMR. Strategies that included a combination of removal efforts and deterrents resulted in the largest decreases in Silver Carp abundance in the upper pools of the UMR. Furthermore, scenarios that targeted source populations of Silver Carp rather than sink populations resulted in larger decreases in Silver Carp abundance at the invasion front. The effectiveness of these combined simulated strategies also depended on the location of Silver Carp recruitment. Our work suggests that an understanding of Silver Carp metapopulation dynamics may be important for control efforts and could help to inform the management of Silver Carp in the UMR.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2019

Morphological identification of Bighead Carp, Silver Carp, and Grass Carp eggs using random forests machine learning classification

Visual identification of fish eggs is difficult and unreliable due to a lack of information on the morphological egg characteristics of many species. We used random forests machine learning to predict the identity of genetically identified Bighead Carp Hypophthalmichthys nobilis , Grass Carp Ctenopharyngodon idella , and Silver Carp H. molitrix eggs based on egg morphometric and environmental characteristics. Family, genus, and species taxonomic-level random forests models were explored to assess the performance and accuracy of the predictor variables. The egg characteristics of Bighead Carp, Grass Carp, and Silver Carp were similar, and they were difficult to distinguish from one another. When combined into a single invasive carp class, the random forests models were ≥ 97% accurate at identifying invasive carp eggs, with a ≤5% false positive rate. Egg membrane diameter was the most important predictive variable, but the addition of ten other variables resulted in a 98% success rate for identifying invasive carp eggs from 26 other upper Mississippi River basin species. Our results revealed that a combination of morphometric and environmental measurements can be used to identify invasive carp eggs. Similar machine learning approaches could be used to identify the eggs of other fishes. These results will help managers more easily and quickly assess invasive carp reproduction.

Iowa↗