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At least 541 records · Page 30Linked to original sources
USGS2020

Freshwater neurotoxins and concerns for human, animal, and ecosystemhealth: A review of anatoxin-a and saxitoxin

Toxic cyanobacteria are a concern worldwide because they can adversely affect humans, animals, and ecosystems. However, neurotoxins produced by freshwater cyanobacteria are understudied relative to microcystin. Thus, the objective of this critical review was to provide a comprehensive examination of the modes of action, production, fate, and occurrence of the freshwater neurotoxins anatoxin-a and saxitoxin as they relate to human, animal, and ecosystem health. Literature on freshwater anatoxin-a and saxitoxin was obtained and reviewed for both laboratory and field studies. Current (2020) research identifies as many as 41 anatoxin-a producing species and 15 saxitoxin-producing species of freshwater cyanobacteria. Field studies indicate that anatoxin-a and saxitoxin have widespread distribution, and examples are given from every continent except Antarctica. Human and animal health concerns can range from acute to chronic. However, few researchers studied chronic or sublethal effects of freshwater exposures to anatoxin-a or saxitoxin. Ecosystemhealth also is a concern, as the effects of toxicity may be far reaching and include consequences throughout the food web. Several gaps in knowledgewere identified for anatoxin-a and saxitoxin, including triggers of production and release, environmental fate and degradation, primary and secondary exposure routes, diel variation, food web effects, effects of cyanotoxin mixtures, and sublethal health effects on individual organisms and populations. Despite the gaps, this critical review facilitates our current understanding of freshwater neurotoxins and thus can serve to guide future research on anatoxin-a, saxitoxin, and other cyanotoxins.

Science of the Total Environment↗
USGS2023

Modular compositional learning improves 1D hydrodynamic lake model performance by merging process-based modeling with deep learning

Hybrid Knowledge-Guided Machine Learning (KGML) models, which are deep learning models that utilize scientific theory and process-based model simulations, have shown improved performance over their process-based counterparts for the simulation of water temperature and hydrodynamics. We highlight the modular compositional learning (MCL) methodology as a novel design choice for the development of hybrid KGML models in which the model is decomposed into modular sub-components that can be process-based models and/or deep learning models. We develop a hybrid MCL model that integrates a deep learning model into a modularized, process-based model. To achieve this, we first train individual deep learning models with the output of the process-based models. In a second step, we fine-tune one deep learning model with observed field data. In this study, we replaced process-based calculations of vertical diffusive transport with deep learning. Finally, this fine-tuned deep learning model is integrated into the process-based model, creating the hybrid MCL model with improved overall projections for water temperature dynamics compared to the original process-based model. We further compare the performance of the hybrid MCL model with the process-based model and two alternative deep learning models and highlight how the hybrid MCL model has the best performance for projecting water temperature, Schmidt stability, buoyancy frequency, and depths of different isotherms. Modular compositional learning can be applied to existing modularized, process-based model structures to make the projections more robust and improve model performance by letting deep learning estimate uncertain process calculations.

Journal of Advances in Modeling Earth Systems↗
USGS2017

At the forefront: evidence of the applicability of using environmental DNA to quantify the abundance of fish populations in natural lentic waters with additional sampling considerations

Environmental DNA (eDNA) sampling has proven to be a valuable tool for detecting species in aquatic ecosystems. Within this rapidly evolving field, a promising application is the ability to obtain quantitative estimates of relative species abundance based on eDNA concentration rather than traditionally labor-intensive methods. We investigated the relationship between eDNA concentration and Arctic char ( Salvelinus alpinus ) abundance in five well-studied natural lakes; additionally, we examined the effects of different temporal (e.g., season) and spatial (e.g., depth) scales on eDNA concentration. Concentrations of eDNA were linearly correlated with char population estimates ( = 0.78) and exponentially correlated with char densities ( = 0.96 by area; 0.82 by volume). Across lakes, eDNA concentrations were greater and more homogeneous in the water column during mixis; however, when stratified, eDNA concentrations were greater in the hypolimnion. Overall, our findings demonstrate that eDNA techniques can produce effective estimates of relative fish abundance in natural lakes. These findings can guide future studies to improve and expand eDNA methods while informing research and management using rapid and minimally invasive sampling.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2020

Source-tracking approach for detecting and identifying sources of wastewater in waters of Hawaiʻi

Elevated concentrations of nutrients and the fecal-indicator bacteria enterococci are occasionally detected in Hawai‘i’s surface waters by the State of Hawai‘i Department of Health Clean Water Branch. Management efforts to improve the water quality of surface waters are complicated by the fact that nutrients and enterococci can originate from several sources, including wastewater, animal waste, and soils. Wastewater often is the suspected source of nutrients and bacteria, but the source may not always be unequivocally identifiable from the Clean Water Branch’s routine monitoring efforts. This report—prepared in cooperation with the State of Hawai‘i Department of Health Clean Water Branch—describes a source-tracking approach for Hawai‘i that is meant to help investigators determine whether wastewater is present in the environment and where wastewater might be originating, if it is present. Wastewater sources include domestic wastewater entering the environment through on-site disposal systems and municipal wastewater entering the environment through leaky sewer systems or injection-well disposal systems. The source-tracking approach relies on the use of field-measured water properties and multiple chemical tracers of wastewater, including optical brighteners, nutrients, hydrogen and oxygen isotopes in water, nitrogen and oxygen isotopes in nitrate, organic waste compounds, and human-use pharmaceutical compounds. The source-tracking approach proposes the following sequence of steps for investigators to execute: (1) gather background information on the study area, (2) conduct trolling-instrument surveys of physical properties of surface water and identify groundwater-discharge locations, (3) collect water samples at reconnaissance sites and analyze the samples for detergent optical brighteners and specific conductance, (4) collect water samples at targeted sites and have appropriate laboratories analyze the samples for chemical tracers of wastewater, and (5) evaluate analytical results for chemical tracers of wastewater and conclude whether wastewater is present in sampled waters. The conclusions can guide management and stakeholder efforts to protect and improve the quality of Hawai‘i’s water resources.

Hawaii↗
USGS1996

The age and thermal history of Cerro Rico de Potosi, Bolivia

Cerro Rico de Potosi, Bolivia, is the world's largest silver deposit and has been mined since the sixteenth century for silver, and for tin and zinc during the twentieth century, together with by-product copper and lead. The deposit consists primarily of veins that cut an altered igneous body that we interpret to be a dacitic volcanic dome and its underlying tuff ring and explosion breccia. The deposit is compositionally and thermally zoned, having a core of cassiterite, wolframite, bismuthinite, and arsenopyrite surrounded by a peripheral, lower-temperature mineral assemblage consisting principally of sphalerite, galena, lead sulfosalt, and silver minerals. The low-temperature assemblage also was superimposed on the high-temperature assemblage in response to cooling of the main hydrothermal system. Both the dacite dome and the ore fluids were derived from a larger magmatic/hydrothermal source at depth. The dome was repeatedly fractured by recurrent movement on the fault system that guided its initial emplacement. The dome was extruded at 13.8 ± 0.2 Ma (2σ), based on U-Th-Pb dating of zircon. Mineralization and alteration occurred within about 0.3 my of dome emplacement, as indicated by a 40 Ar/ 39 Ar date of 13.76 ± 0.10Ma (1σ) for sericite from the pervasive quartz-sericite-pyrite alteration associated with the main-stage, high-temperature, mineralization. The last thermal event able to reset zircon fission tracks occurred no later than 12.5 ± 1.1 Ma (1σ), as indicated by fission-tract dating. Minor sericite, and magmatic-steam alunite veins, were episodically formed around 11 Ma and between 8.3 and 5.7 Ma; the younger episodes occurring at the time of extensional fracturing at Cerro Rico and wide-spread volcanism in the adjacent Los Frailes volcanic field. None of these younger events appear to be significant thermal/mineralizing events; the exceptionally flat thermal release pattern of 39 Ar from sericite and the results of the fission-tract dating of zircon show that none of the younger events was hot enough, and lasted long enough, to cause significant loss of Ar or annealing of zircon fission tracks. U-Th-Pb dating of zircon cores indicates a Precambrian progenitor for some zircons, and REE analyses of dated samples of hydrothermally altered dacite show the presence of a prominent positive Eu anomaly, which constrains interpretations of the origin and evolution of the magmatic/hydrothermal system.

Cerro Rico de Potosi↗
USGS1984

SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN.

Shuttle Imaging Radar provides a pictorial framework to guide exploration for mineral resources (potential placers), groundwater sources, and prehistoric archaeological sites in the Western Desert of Egypt and Sudan. Documented penetration by the SIR-A signal of dry surficial sediment to depths of a meter or more revealed bedrock geologic features and networks of former stream valleys otherwise concealed beneath windblown sand, alluvium, and colluvial deposits. 'Radar units' mapped on SIR-A images according to relative brightness and degree of mottling correspond to subsurface geologic and topographic features identified in more than 50 test pits. Petrologic examination of pit samples confirms that a variety of depositional environments existed in this now hyper-arid region before it was mantled by windblown sand sheets and dunes. Wet sand was discovered in two buried valleys shown on the radar images and located in the field with the aid of co-registered maps and Landsat images, and a satellite navigation device. Buried valleys whose streams once traversed mineralized zones are potential sites of placers (gold, tin).

Conference Paper↗
USGS2000

Studies of volcanoes of Alaska by satellite radar interferometry

Interferometric synthetic aperture radar (InSAR) has provided a new imaging geodesy technique to measure the deformation of volcanoes at tens-of-meter horizontal resolution with centimeter to subcentimeter vertical precision. The two-dimensional surface deformation data enables the construction of detailed numerical models allowing the study of magmatic and tectonic processes beneath volcanoes. This paper summarizes our recent: InSAR studies over the Alaska-Aleutian volcanoes, which include New Trident, Okmok, Akutan, Augustine, Shishaldin, and Westdahl volcanoes. The first InSAR surface deformation over the Alaska volcanoes was applied to New Trident. Preliminary InSAR study suggested that New Trident volcano experienced several centimeters inflation from 1993 to 1995. Using the InSAR technique, we studied the 1997 eruption of Okmok. We have measured ???1.4 m deflation during the eruption, ???20 cm pre-eruptive inflation during 1992 to 1995, and >10 cm post-eruptive inflation within a year after the eruption, and modeled the deformations using Mogi sources. We imaged the ground surface deformation associated with the 1996 seismic crisis over Akutan volcano. Although seismic swarm did not result in an eruption, we found that the western part of the volcano uplifted ???60 cm while the eastern part of the island subsided. The majority of the complex deformation field at the Akutan volcano was modeled by dike intrusion and Mogi inflation sources. Our InSAR results also indicate that the pyroclastic flows from last the last eruption have been undergoing contraction/subsidence at a rate of about 3 cm per year since 1992. InSAR measured no surface deformation before and during the 1999 eruption of Shishaldin and suggested the eruption may be a type of open system. Finally, we applied satellite radar interferometry to Westdahl volcano which erupted 1991 and has been quiet since. We discovered this volcano had inflated about 15 cm from 1993 to 1998. In summary, satellite radar interferometry can not only be used to study a volcanic eruption, but also to detect aseismic deformation at quiescent volcanoes preceding a seismic swarm; it is a useful technique to study volcanic eruptions as well as to guide scientists to better focus their monitoring efforts.

Alaska↗
USGS2019

Volcano deformation: Insights into magmatic systems

Volcano geodesy is the branch of geodetic science that deals with the changing shapes of volcanoes, whether large or small, deep-seated or surficial. Together with seismicity and volcanic gas flux, deformation of the ground surface can be a key indicator of subsurface conditions and processes at volcanoes—information that not only improves scientific understanding of magmatic systems but also is useful for assessing volcano hazards and mitigating their potential consequences. To take full advantage of such information requires detailed characterization of the deformation field in space and time. Currently, no single geodetic technique is capable of providing both the high spatial and temporal resolution required. However, important advances have been made recently by combining information from real-time in situ sensors such as continuous GPS, strainmeters, and tiltmeters with repeated campaign-style GPS, microgravity, interferometric synthetic aperture radar (InSAR), lidar, and photogrammetric observations. Continuous real-time data constrain the timing but not necessarily the spatial extent and pattern of deformation, whereas InSAR provides detailed spatial information but only at intervals of several days to weeks. Repeated microgravity surveys, when combined with independent measurements of surface height, are uniquely sensitive to changes in subsurface mass distribution and therefore can be used to distinguish among processes driven by magma, hydrous fluids, or gas. Simultaneous analysis of multiple geodetic datasets, especially when guided by information from global volcano databases and numerical simulations of volcanic processes and products, can provide a statistical basis for outcome prediction and serve as a guide for additional observations. In the foreseeable future, interactions among magmatic, tectonic, and hydrothermal systems will be monitored and modeled at regional scale in real time, enabling new insights into Earth’s subsurface environment.

Book chapter↗
USGS2005

South Fork Iowa River watershed selected for a national water-quality study

The U.S. Geological Survey (USGS) is studying seven watersheds across the Nation to better understand how natural factors and agricultural management practices (AMPs) affect the transport of water and chemicals. Natural factors include climate and landscape (soil type, topography, geology), and AMPs include practices related to tillage, irrigation, and chemical application. The study approach is similar in each watershed so that we can compare and contrast the results and more accurately predict conditions in other agricultural settings. Study objectives Understand the links between the sources of water and agricultural chemicals (nutrients and pesticides) and their behavior and transport through the environment Predict the behavior and transport of water and agricultural chemicals in other agricultural areas not being studied Evaluate what the study results mean for management of water and water quality in a variety of agricultural settings We appreciate your help We are working with local growers and land owners to gain access to study sites. We also need information about the watershed and about current as well as historical agricultural management practices—past practices also affect concentrations of agricultural chemicals in ground and surface water. We will report the findings of the study in public meetings and in publications. These findings will provide information that will be useful for improving agricultural management locally and nationally, and will guide future studies in other watersheds. Why study the South Fork Iowa River watershed? The South Fork Iowa River and the other watersheds represent nationally important agricultural settings (chemical use, crops, and AMPs) and natural settings (climate, soils, topography, and geology). South Fork Iowa River, which is part of the Iowa River watershed, is representative of corn and soybean row cropping in the Midwest. Other features of the watershed that are relevant to this study: Use of agricultural chemicals: Commonly used chemicals include herbicides such as atrazine, acetochlor, metolachlor, and glyphosate; and fertilizers, both manure and chemical. Distinct natural setting: Low relief topography with common depressions that formerly formed ponds and wetlands and that are now drained by an extensive network of drainage tiles and ditches. Variety of agricultural management practices: AMPs include both tillage and no-tillage of fields used for corn and soybean production; production of large numbers of hogs in concentrated animal feeding facilities; small grassy riparian buffer zones commonly used to reduce overland runoff. Water-quality issues: Herbicides and nutrients have been frequently detected in Iowa surface and ground water, including in drinking-water wells (findings of USGS studies since the 1990s).

Iowa, Minnesota↗
USGS2021

SSA task force on diversity, equity, and inclusion: Toward a changing, inclusive future in earthquake science

In the United States, a wide variety of studies show that the geoscience community does not reflect the broader societal makeup (e.g., Velasco and Jaurrieta de Velasco, 2010; Dutt, 2020; Howley, 2020). In fact, only about 10% of all Science, Technology, Engineering, and Mathematics (STEM) Ph.D. degrees are awarded to people of color, although they represent more than a third of the population (Dutt, 2020). These numbers have changed little over the past 40 yr (e.g., Bernard and Cooperdock, 2018; Dutt, 2020). Recent events in the United States have again raised awareness of this discrepancy in many fields; similar divergences may be present throughout the world. This discrepancy represents a tremendous loss of talent and contributes to ongoing bias and racism. As the premier international seismological professional society, Seismological Society of America (SSA) is committed, as stated in its ethics policy, to “freedom and transparency in research and education, which should be conducted in a supportive, inclusive, and respectful environment, free from any discrimination, harassment or bullying.” SSA convened the SSA Diversity, Equity, and Inclusion (DEI) Task Force to identify specific and actionable recommendations that the Society can take to start to address the significant issues surrounding the systematic underrepresentation in seismology and related geosciences by marginalized groups on both short- and long- term time horizons. This report, written by the Task Force, outlines actionable items that SSA can undertake as well as a framework by which progress can be measured to help guide the Society and its members forward as a community to make earthquake science more just, equitable, diverse, and inclusive. We recognize that this document cannot address the multiple individual, cultural, and historical barriers that some members may face (e.g., Núñez et al., 2020), nor can it reflect all possibilities or all recommended practices (e.g., Ali et al., 2021). What this document does represent, however, is the beginning of what we hope to be a significant cultural change in how we conduct earthquake science as an organization, not the end of this process as the Task Force fulfills its charter. As a note, some of the recommendations that the Task Force has outlined here have already been implemented within SSA or are actively being considered. For completeness, we still include them here because this highlights the commitment to change that SSA leadership has embraced.

Seismological Research Letters↗
USGS2015

High‐resolution trench photomosaics from image‐based modeling: Workflow and error analysis

Photomosaics are commonly used to construct maps of paleoseismic trench exposures, but the conventional process of manually using image‐editing software is time consuming and produces undesirable artifacts and distortions. Herein, we document and evaluate the application of image‐based modeling (IBM) for creating photomosaics and 3D models of paleoseismic trench exposures, illustrated with a case‐study trench across the Wasatch fault in Alpine, Utah. Our results include a structure‐from‐motion workflow for the semiautomated creation of seamless, high‐resolution photomosaics designed for rapid implementation in a field setting. Compared with conventional manual methods, the IBM photomosaic method provides a more accurate, continuous, and detailed record of paleoseismic trench exposures in approximately half the processing time and 15%–20% of the user input time. Our error analysis quantifies the effect of the number and spatial distribution of control points on model accuracy. For this case study, an ∼87 m 2 exposure of a benched trench photographed at viewing distances of 1.5–7 m yields a model with <2 cm root mean square error (rmse) with as few as six control points. Rmse decreases as more control points are implemented, but the gains in accuracy are minimal beyond 12 control points. Spreading control points throughout the target area helps to minimize error. We propose that 3D digital models and corresponding photomosaics should be standard practice in paleoseismic exposure archiving. The error analysis serves as a guide for future investigations that seek balance between speed and accuracy during photomosaic and 3D model construction.

Bulletin of the Seismological Society of America↗
USGS1901

Twenty-First Annual report of the Director of the United States Geological Survey, 1899-1900: Part VII - Texas

Area treated. —The Black and Grand prairies of Texas and southern Indian Territory comprise about 50,000 square miles (see Pl. LXV, in pocket)—an area equal to that of fifty of the quadrangles mapped and described by the United States Geological Survey in its Geologic Atlas of the United States. The accompanying general geologic map (Pl. LXVI, in pocket) is a condensed presentation of the geology usually shown on that number of atlas sheets as published in folio form. Most of these quadrangles have been studied by the writer and his former assistants. Sources of data. —An entirely satisfactory presentation of these results is still impossible by reason of the lack of adequate maps. The topographic maps of the United States Geological Survey, which cover 24 of the 50 units of area, were made in the earlier years of the Survey and with a contour interval insufficient for the expression of the geology. For the remaining portion of the area it was necessary to use as a base the Land Office maps of the State of Texas. The conclusions herein presented, often condensed in a short paragraph, are founded upon a large amount of paleontologic, stratigraphic, and topographic data. The results, so far as they refer to the Black and Grand prairies, are the outcome of studies made by the writer since 1882, sometimes independently, sometimes with the assistance of the United States Geological Survey, and during two years in connection with the Texas Geological Survey. In times past he has been assisted in this work by his former students, C. C. McCulloch, now captain, U. S. A.; Messrs. Wilson T. Davidson and L. T. Dashiel; Mr. Joseph A. Taff, now of the United States Geological Survey; Dr. J. W. Stone, Mr. N. F. Drake, and Mr. G. H. Ragsdale. Inasmuch as the details which these gentlemem worked out were problems of the writer's suggestion, he has incorporated them into this paper, and here acknowledges indebtedness therefor. Upon the writer's retirement from the Texas Survey, Mr. Taff continued the work of mapping the region. He published two reports, which have been freely used and which have been of great assistance in the preparation of this paper. Importance of paleontology. —In addition to the collection of the data which appear in the text and illustrations, much paleontologic research has been necessary in order to classify the formations. Paleontology is the most reliable guide in determining the position of any bed in the geologic series with a view to ascertaining the depth, from any particular portion of the surface, of the underground waters in the Cretaceous regions of Texas. If a few species of fossils, such as can be found in any locality, be sent to one familiar with the sequence of the beds, he can predict within a few feet the depth below the surface of any particular water-bearing stratum in the series. It was a labor of years to disentangle the preexisting confusion concerning the occurrence and succession of these fossils and their bearings upon the determination and definition of the strata. Their further consideration has been left to Mr. T. W. Stanton, who, it is presumed, will make final publication of the descriptions and the scientific results. This is not a final and complete report. Detailed field work is desirable in many localities. Chemical analyses of water and illustrations of typical scenery should be more complete, but these were not obtainable with the means and time at the writer's disposal. When appreciation of geologic investigation shall have been awakened in Texas and the region under discussion shall have been studied more closely by resident students, in the manner now common in other parts of the United States, the data here presented will be largely increased and refined, and the conclusions will doubtless be correspondingly amended and rectified.

Texas↗
USGS2012

Metal dispersion resulting from mining activities in coastal environments: A pathways approach

Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

Oceanography↗
USGS2018

Improving earthquake rupture forecasts using California as a guide

This article discusses ways in which earthquake rupture forecast models might be improved. Because changes are most easily described in the context of specific models, the third Uniform California Earthquake Rupture Forecast (UCERF3) and its presumed successor, UCERF4, is used as a basis for discussion. Virtually all of the issues and possible improvements discussed are nevertheless general and should therefore be applicable to other regions as well. Two common themes are a need for better epistemic uncertainty representation and the potential utility of physics‐based simulators. Given the large number of possible improvements, coupled with challenges in defining the potential value of each, which will vary among uses, community feedback is invaluable in terms of setting priorities. We should also strive to define more objective valuation metrics.

Seismological Research Letters↗
USGS1988

Selawik National Wildlife Refuge land cover mapping project users guide

Title III of the Alaska National Interest Lands Conservation Act (ANILCA, 1980) established the Selawik National Wildlife Refuge (SNWR). Section 304 of the Act requires the Secretary of Interior to "prepare, and from time to time revise, a comprehensive conservation plan" for the refuge. Before developing a plan for the refuge, the Secretary shall "identify and describe--a) the populations and habitats of the fish and wildlife resources of the refuge; b) the special values of the refuge as well as any other archeological, cultural, ecological, geological, historical, palentological, scenic, or wilderness value of the refuge; c) areas within the refuge that are suitable for use as administrative sites or visitor facilities...; d) present the potential requirements for access with respect to the refuge...; and e) significant problems which may adversely affect the populations and habitats of fish and wildlife identified and described..." (ANILCA, 1980). Vegetation, water, and terrain (elevation, slope, and aspect) are the components of habitat and can be used in the determination of the above requirements. The U.S. Fish & Wildlife Service (USFWS) has the responsibility for collecting the resource information to address the research, management, development and planning requirements identified in Section 304. Because of the brief period provided by the Act for data collection, habitat mapping, and habitat assessment, the USFWS in cooperation with the U.S. Geological Survey's EROS Field Office, used digital Landsat multispectral scanner (MSS) data and digital terrain data to produce land cover and terrain maps. A computer assisted digital analysis of Landsat MSS data was used because coverage by aerial photographs was incomplete for the refuge and because the level of detail obtained from Landsat data was adequate to meet most USFWS research, management and planning needs. Relative cost and time requirements were also factors in the decision to use the digital analysis approach.

Alaska↗
USGS1987

Yukon Flats National Wildlife Refuge land cover mapping project user's guide

Title III of the Alaska National Interest Lands Conservation Act (ANILCA, 1980) established the Yukon Flats National Wildlife Refuge (YFNWR). Section 304 of the Act requires the Secretary of Interior to "prepare, and from time to time revise, a comprehensive conservation plan" for the refuge. Before developing a plan for the refuge, the Secretary shall "identify and describe--a) the populations and habitats of the fish and wildlife resources of the refuge; b) the special values of the refuge as well as any other archeological, cultural, ecological, geological , historical, palentological, scenic, or wilderness value of the refuge; c) areas within the refuge that are suitable for use as administrative sites or visitor facilities...; d) present the potential requirements for access with respect to the refuge...; and e) significant problems which may adversely affect the populations and habitats of fish and wildlife identified and described..." (ANILCA, 1980). Vegetation, water, and terrain (elevation, slope, and aspect) are the components of habitat and can be used in the determination of the above requirements. The U. S. Fish & Wildlife Service (USFWS) has the responsibility for collecting the resource information to address the research, management, development and planning requirements identified in Section 304. Because of the brief period provided by the Act for data collection, habitat mapping, and habitat assessment, the USFWS in cooperation with the U.S. Geological Survey's EROS Field Office, used digital Landsat multispectral scanner (MSS) data and digital terrain data to produce land cover and terrain maps. A computer assisted digital analysis of Landsat MSS data was used because coverage by aerial photographs was incomplete for much of the refuge and because the level of detail obtained from Landsat data was adequate to meet most USFWS research, management and planning needs. Relative cost and time requirements were also factors in the decision to use the digital analysis approach.

Alaska↗
USGS2017

The Wetland and Aquatic Research Center strategic science plan

Introduction The U.S. Geological Survey (USGS) Wetland and Aquatic Research Center (WARC) has two primary locations (Gainesville, Florida, and Lafayette, Louisiana) and field stations throughout the southeastern United States and Caribbean. WARC’s roots are in U.S. Fish and Wildlife Service (USFWS) and National Park Service research units that were brought into the USGS as the Biological Research Division in 1996. Founded in 2015, WARC was created from the merger of two long-standing USGS biology science Centers—the Southeast Ecological Science Center and the National Wetlands Research Center—to bring together expertise in biology, ecology, landscape science, geospatial applications, and decision support in order to address issues nationally and internationally. WARC scientists apply their expertise to a variety of wetland and aquatic research and monitoring issues that require coordinated, integrated efforts to better understand natural environments. By increasing basic understanding of the biology of important species and broader ecological and physiological processes, this research provides information to policymakers and aids managers in their stewardship of natural resources and in regulatory functions. This strategic science plan (SSP) was developed to guide WARC research during the next 5–10 years in support of Department of the Interior (DOI) partnering bureaus such as the USFWS, the National Park Service, and the Bureau of Ocean Energy Management, as well as other Federal, State, and local natural resource management agencies. The SSP demonstrates the alignment of the WARC goals with the USGS mission areas, associated programs, and other DOI initiatives. The SSP is necessary for workforce planning and, as such, will be used as a guide for future needs for personnel. The SSP also will be instrumental in developing internal funding priorities and in promoting WARC’s capabilities to both external cooperators and other groups within the USGS.

Open-File Report↗
USGS2007

Quaternarymagmatism in the Cascades - Geologic perspectives

Foreward The Cascade magmatic arc is a belt of Quaternary volcanoes that extends 1,250 km from Lassen Peak in northern California to Meager Mountain in Canada, above the subduction zone where the Juan de Fuca Plate plunges beneath the North American Plate. This Professional Paper presents a synthesis of the entire volcanic arc, addressing all 2,300 known Quaternary volcanoes, not just the 30 or so visually prominent peaks that comprise the volcanic skyline. Study of Cascade volcanoes goes back to the geological explorers of the late 19th century and the seminal investigations of Howel Williams in the 1920s and 1930s. However, major progress and application of modern scientific methods and instrumentation began only in the 1970s with the advent of systematic geological, geophysical, and geochemical studies of the entire arc. Initial stimulus from the USGS Geothermal Research Program was enhanced by the USGS Volcano Hazards Program following the 1980 eruption of Mount St. Helens. Together, these two USGS Programs have provided more than three decades of stable funding, staffing, and analytical support. This Professional Paper summarizes the resultant USGS data sets and integrates them with the parallel contributions of other investigators. The product is based upon an all-encompassing and definitive geological database, including chemical and isotopic analyses to characterize the rocks and geochronology to provide the critical time constraints. Until now, this massive amount of data has not been summarized, and a systematic and uniform interpretation firmly grounded in geological fact has been lacking. Herein lies the primary utility of this Cascade volume. It not only will be the mandatory starting point for new workers, but also will provide essential geological context to broaden the perspectives of current investigators of specific Cascade volcanoes. Wes Hildreth's insightful understanding of volcanic processes and his uncompromising scientific integrity make him uniquely qualified to present this synthesis. During more than three decades of volcanological studies, he has carried out comprehensive investigations of Mount Adams, Mount Baker, the Three Sisters, and the Simcoe Mountains Volcanic Field. He also brings a broad experience in other volcanic arcs, having conducted integrated field and laboratory investigations at several major volcanic centers in the Andes and the Aleutian arcs. His expertise and perspective have been further enhanced by in-depth petrologic studies of caldera environments, primarily in Long Valley, California, and Yellowstone. On the basis of all these field and laboratory investigations and exhaustive literature searches, he has published three definitive petrologic syntheses addressing the passage and transformation of basaltic magmas from their mantle sources through the crust to form the many types of volcanic manifestations at the Earth's surface. A major strength of this Professional Paper is that it adheres to data first and foremost, and only then correlates these data with relevant theories. Petrological and geophysical interpretation is left to the later sections of the volume, and even there is never allowed to stray from the pertinent databases. Hildreth's interpretations are not just idle speculations, but are carefully reasoned inferences firmly based on his thorough evaluation of the observational geological data. Professional Paper 1744 should not be skimmed lightly, in the hope that the salient points will quickly rub off. Instead, every section, indeed every paragraph, presents scholarly observations and insightful interpretations that demand careful and thoughtful study. This volume will influence and guide the course of Cascade investigations for decades to come.

British Columbia, California, Oregon, Washington↗