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At least 1,207 records · Page 67Linked to original sources
USGS2013

Characterization of the Hosgri Fault Zone and adjacent structures in the offshore Santa Maria Basin, south-central California

The Hosgri Fault Zone trends subparallel to the south-central California coast for 110 km from north of Point Estero to south of Purisima Point and forms the eastern margin of the present offshore Santa Maria Basin. Knowledge of the attributes of the Hosgri Fault Zone is important for petroleum development, seismic engineering, and environmental planning in the region. Because it lies offshore along its entire reach, our characterizations of the Hosgri Fault Zone and adjacent structures are primarily based on the analysis of over 10,000 km of common-depth-point marine seismic reflection data collected from a 5,000-km2 area of the central and eastern parts of the offshore Santa Maria Basin. We describe and illustrate the along-strike and downdip geometry of the Hosgri Fault Zone over its entire length and provide examples of interpreted seismic reflection records and a map of the structural trends of the fault zone and adjacent structures in the eastern offshore Santa Maria Basin. The seismic data are integrated with offshore well and seafloor geologic data to describe the age and seismic appearance of offshore geologic units and marker horizons. We develop a basin-wide seismic velocity model for depth conversions and map three major unconformities along the eastern offshore Santa Maria Basin. Accompanying plates include maps that are also presented as figures in the report. Appendix A provides microfossil data from selected wells and appendix B includes uninterpreted copies of the annotated seismic record sections illustrated in the chapter. Features of the Hosgri Fault Zone documented in this investigation are suggestive of both lateral and reverse slip. Characteristics indicative of lateral slip include (1) the linear to curvilinear character of the mapped trace of the fault zone, (2) changes in structural trend along and across the fault zone that diminish in magnitude toward the ends of the fault zone, (3) localized compressional and extensional structures characteristic of constraining and releasing bends and stepovers, (4) changes in the sense and magnitude of vertical separation along strike within the fault zone, and (5) changes in downdip geometry between the major traces and segments of the fault zone. Characteristics indicative of reverse slip include (1) reverse fault geometries that occur across major strands of the fault zone and (2) fault-bend folds and localized thrust faults that occur along the northern and southern reaches of the fault. Analyses of high-resolution, subbottom profiler and side-scan sonar records indicate localized Holocene activity along most of the extent of the fault zone. Collectively, these features are the basis of our characterization of the Hosgri Fault Zone as an active, 110-km-long, convergent right-oblique slip (transpressional) fault with identified northern and southern terminations. This interpretation is consistent with recently published analyses of onshore geologic data, regional tectonic kinematic models, and instrumental seismicity.

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USGS1998

Ground water and surface water: A single resource

The importance of considering ground water and surface water as a single resource has become increasingly evident. Issues related to water supply, water quality, and degradation of aquatic environments are reported on frequently. The interaction of ground water and surface water has been shown to be a significant concern in many of these issues. Contaminated aquifers that discharge to streams can result in long-term contamination of surface water; conversely, streams can be a major source of contamination to aquifers. Surface water commonly is hydraulically connected to ground water, but the interactions are difficult to observe and measure. The purpose of this report is to present our current understanding of these processes and activities as well as limitations in our knowledge and ability to characterize them.

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USGS2007

About the geologic map in the National Atlas of the United States of America

Introduction The geologic map in the National Atlas of the United States of America shows the age, distribution, and general character of the rocks that underlie the Nation, including Alaska, Hawaii, Puerto Rico, and the Virgin Islands (but excluding other small island possessions). (The National Atlas of the United States can be accessed at URL http://nationalatlas.gov/natlas/Natlasstart.asp.) The map depicts the bedrock that lies immediately beneath soils or surficial deposits except where these deposits are so thick and extensive that the type of bedrock beneath them can only be inferred by deep drilling or geophysical methods, or both. Thus, it does not show the extensive glacial deposits of the North Central and Northeastern States, the deep residuum of the Southeastern and South Central States, the relatively thin alluvium along many major rivers and basins, and extensive eolian deposits on the high plains. However, it does show, in a general way, the thick alluvial deposits along the lower Mississippi River and on the Atlantic and Gulf Coastal Plains, and in the deep basins of the western cordillera. The rocks are classified as either sedimentary, volcanic, plutonic, or metamorphic, and their geologic ages are given in terms using a simplified version of the 1999 Geological Society of America geologic time scale. In some places rocks depicted as sedimentary are interlayered with volcanic rocks, including tuff, volcanic breccia, and volcanic flows. Conversely, many of the rocks shown as volcanic include interlayered sedimentary rocks. Plutonic rocks are classified by age and as granitic, intermediate, mafic, or ultramafic, but no similar classification has been attempted for the volcanic rocks in this version of the map. Where sedimentary or volcanic rocks have been metamorphosed but still retain clear evidence of their depositional age and origin, the extent of the metamorphism is shown by a pattern. Where the metamorphism has been so intense that the rocks bear little resemblance to the rocks from which they were derived, they are mapped as gneiss, but the age given is generally the age of the original rocks. The map in the National Atlas is a generalization of a new geologic map of North America that has recently been published by the Geological Society of America. The original compilation was prepared at a scale of 1:2,500,000 for publication at a scale of 1:5,000,000. This generalized version is intended for viewing at scales between about 1:10,000,000 and 1:7,500,000.

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USGS2010

Byproduct mineral commodities used for the production of photovoltaic cells

Rising fossil fuel costs, environmental concerns relating to global climate change, and Government policy to signifcantly increase our Nation's energy independence have placed greater emphasis on the generation of electricity from renewable sources, such as the Sun (light and heat), water, and wind, which for all intents and purposes are inexhaustible resources. Although the total amount of electricity generated from the direct conversion of sunlight through photovoltaic cells is relatively small compared with that from other forms of renewable energy, the rate of growth in the sector is signifcant. The total value of energy of photovoltaic cells produced worldwide increased to nearly 7 gigawatts (GW) in 2008 from 45 megawatts (MW) in 1990, a compound annual growth rate of about 30 percent. In the United States, manufacturing of photovoltaic cells has grown exponentially to about 480 MW in 2008, accounting for 6 percent of world production, from less than 10 MW of photovoltaic capacity in 1990 (Benner, 2007; U.S. Department of Energy, Energy Information Administration, 2010), a compound annual growth rate of approxi-mately 23 percent. A production capacity of 1 GW of electricity [or 8,760 gigawatthours1 (GWh)] is equivalent to the annual electricity requirements for roughly 800,000 average households in the United States (U.S. Department of Energy, Energy Information Administration, 2010). This estimate does not include losses of electricity, such as during transmission through power lines.

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USGS2014

Mercury in the nation's streams - Levels, trends, and implications

Mercury is a potent neurotoxin that accumulates in fish to levels of concern for human health and the health of fish-eating wildlife. Mercury contamination of fish is the primary reason for issuing fish consumption advisories, which exist in every State in the Nation. Much of the mercury originates from combustion of coal and can travel long distances in the atmosphere before being deposited. This can result in mercury-contaminated fish in areas with no obvious source of mercury pollution. Three key factors determine the level of mercury contamination in fish - the amount of inorganic mercury available to an ecosystem, the conversion of inorganic mercury to methylmercury, and the bioaccumulation of methylmercury through the food web. Inorganic mercury originates from both natural sources (such as volcanoes, geologic deposits of mercury, geothermal springs, and volatilization from the ocean) and anthropogenic sources (such as coal combustion, mining, and use of mercury in products and industrial processes). Humans have doubled the amount of inorganic mercury in the global atmosphere since pre-industrial times, with substantially greater increases occurring at locations closer to major urban areas. In aquatic ecosystems, some inorganic mercury is converted to methylmercury, the form that ultimately accumulates in fish. The rate of mercury methylation, thus the amount of methylmercury produced, varies greatly in time and space, and depends on numerous environmental factors, including temperature and the amounts of oxygen, organic matter, and sulfate that are present. Methylmercury enters aquatic food webs when it is taken up from water by algae and other microorganisms. Methylmercury concentrations increase with successively higher trophic levels in the food web—a process known as bioaccumulation. In general, fish at the top of the food web consume other fish and tend to accumulate the highest methylmercury concentrations. This report summarizes selected stream studies conducted by the U.S. Geological Survey (USGS) since the late 1990s, while also drawing on scientific literature and datasets from other sources. Previous national mercury assessments by other agencies have focused largely on lakes. Although numerous studies of mercury in streams have been conducted at local and regional scales, recent USGS studies provide the most comprehensive, multimedia assessment of streams across the United States, and yield insights about the importance of watershed characteristics relative to mercury inputs. Information from other environments (lakes, wetlands, soil, atmosphere, glacial ice) also is summarized to help understand how mercury varies in space and time.

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USGS2018

Cooperative Fish and Wildlife Research Units Program—2017 year in review

The Cooperative Fish and Wildlife Research Units Program was involved in a number of notable events during 2017, many concerning our personnel. Dr. Barry Grand left his position as Leader of the Alabama Cooperative Fish and Wildlife Research Unit to become the Cooperative Units Program Supervisor for the South, replacing Dr. Kevin Whalen who took over as Supervisor for the West. We welcomed Dr. Sarah Converse who left the Patuxent Wildlife Research Center to become Leader of the Washington Cooperative Fish and Wildlife Research Unit. Dr. Amanda Rosenberger joined the Tennessee Cooperative Fishery Research Unit as Assistant Leader, transferring from the Missouri Cooperative Unit. Dr. Scott Carleton left his position as Assistant Unit Leader in New Mexico to become Chief of the Region 2 Migratory Bird Program of the U.S. Fish and Wildlife Service. We said farewell to many colleagues who retired. Their departure is bittersweet as we wish them health, happiness, and wellness in retirement. We will miss their companionship and the extraordinary contributions they have made to the Cooperative Fish and Wildlife Research Units Program and conservation. The Cooperative Fish and Wildlife Research Units Program has a record high number of vacant scientist positions due to a combination of retirements and base funding short-falls. These issues are affecting our ability to meet cooperator needs. Yet, we remain highly productive. For example, this year we released a report ( https://doi.org/10.3133/cir1427 ) containing abstracts of nearly 600 of our research projects, covering thematic areas ranging from advanced technologies to wildlife diseases. We provided highly competent, trained scientists and natural resource managers for our cooperators’ workforce. We delivered technical training and guidance to professional practitioners. We provided critical information to cooperators for decisions on species status assessments and management of species of greatest conservation need. This year we had an active presence at major national meetings, including the North American Wildlife and Natural Resources Conference where we co-sponsored a workshop on continuing education as a means to bridge the gap between science and management. During the coming year, with support from the U.S. Geological Survey and our cooperators, we intend to reduce the number of vacancies in the program. It will take time and active support of our cooperators to get back to full strength, but I am committed to this goal and encouraged by the resolve of our partners. We look forward to an even more productive year in 2018!

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USGS2019

U.S. Geological Survey energy and wildlife research annual report for 2019

Access to affordable and reliable energy remains a critical need for people and the economy. To satisfy society’s demand for energy, the United States is expanding access to vast natural resources to produce electricity as well as petroleum and natural gas products. Development of our Nation’s energy resources, however, often conflicts directly with the equally vast fish and wildlife resources, which contribute billions of dollars to the economy through harvest, recreation, and services to humans and agriculture. The effects of energy development on living resources include fragmentation of populations, degradation or loss of habitat, and mortality of birds, bats, fish, and other wildlife interacting with energy generation facilities. Thus, an expanding energy infrastructure results in new requirements for land and ocean conversion for project siting and operational decisions to minimize risk to fish and wildlife resources. U.S. Geological Survey (USGS) scientists partner with more than 150 Federal, State, and local government agencies; Tribal nations; academic institutions; and nongovernmental organizations to deliver timely and relevant information on pressing resource management issues. This report summarizes ongoing USGS research projects and publications related to the impacts of energy development on fish and wildlife resources, tools to assess those impacts, and solutions to avoid or minimize risk. This information helps decision makers balance development with stewardship of the Nation’s fish and wildlife heritage.

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USGS2021

U.S. Geological Survey wildland fire science strategic plan, 2021–26

The U.S. Geological Survey (USGS) Wildland Fire Science Strategic Plan defines critical, core fire science capabilities for understanding fire-related and fire-responsive earth system processes and patterns, and informing management decision making. Developed by USGS fire scientists and executive leadership, and informed by conversations with external stakeholders, the Strategic Plan is aligned with the needs of the fire science stakeholder community–fire, land, natural resource, and emergency managers from Federal, State, Tribal, and community organizations, as well as members of the scientific community. The Strategic Plan is composed of four integrated priorities, each with associated goals and specific strategies for accomplishing the goals: Priority 1: Produce state-of-the-art, actionable fire science; Priority 2: Engage stakeholders in science production and science delivery; Priority 3: Effectively communicate USGS fire science capacity, products, and information to a broad audience; and Priority 4: Enhance USGS organizational structure and advance support for fire science. The priorities of this Strategic Plan define the USGS’s commitment to producing and delivering cutting edge fire science, information, and decision-support tools in support of national, regional, and local priorities and stakeholder needs.

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USGS2023

U.S. Geological Survey science vision for native freshwater mussel research in the United States

Executive Summary North America is a global center for native freshwater mussel (order Unionida, hereinafter “mussels”) diversity, with more than 350 species. Mussels are among the most imperiled fauna on the planet. Reasons for both local and widespread declines in mussels are mostly unknown, although the threats may include habitat loss and fragmentation, diseases, environmental contaminants, altered flow regimes, migration barriers to larval hosts, non-native species, and climate change. Over the past three decades, research on mussels has been substantial. Nevertheless, current conservation and management efforts are limited by significant information gaps. For example, the effects of emerging stressors on mussels are largely unknown and identifying when habitats are rehabilitated and suitable for reestablishment of mussels remains challenging. Additionally, historical and current information on the distribution, taxonomy, and life histories are often unreliable or lacking altogether, and more reliable information is needed for many species. We identified focal research themes, goals, and objectives where research on mussels is needed based on information gaps identified through conversations with resource partners across local, regional, and national organizations. Research on biodiversity seeks to enhance the diversity of mussel species and populations to support healthy aquatic ecosystems. Research on emerging stressors seeks to improve the understanding of how mussel species, populations, and communities respond to emerging stressors, including environmental contaminants and climate change. Research on conservation seeks to enhance the recovery of species and populations and to identify data gaps limiting the conservation of mussels and their habitats. Mussels are in urgent need of proactive conservation because they are an integral part of our natural heritage, enhance biodiversity, and provide vital ecological services that support freshwater ecosystems. The U.S. Geological Survey (USGS) has been, and continues to be, a leader in mussel research. Although the USGS is well suited to address the broad-scale multidisciplinary research needed to conserve mussels, the USGS has had substantial loss of scientists with mussel expertise over the past 20 years. However, the breadth of the USGS expertise on mussels can be leveraged internally across other USGS mission and program areas and externally across research partners. Given the breadth and scope of the issues facing mussels across the United States, the research themes outlined in this science vision can only be accomplished through extensive collaborations between the USGS and the full spectrum of natural resource partners, including other Federal and State agencies, Tribal organizations, universities, industries, and nongovernmental organizations.

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USGS1978

The Energy Lands Program of the U.S. Geological Survey, fiscal year 1976

The Energy Lands Program of the U.S. Geological Survey comprises several projects that conduct basic and interpretive earth-science investigations into the environmental aspects of energy-resource recovery, transmission, and conversion. More than half the coal reserves of the United States occur west of the Mississippi River; therefore, the program concentrates mostly on coal-producing regions in the Western interior. Additional studies involve the oil-shale region in Colorado, Wyoming, and Utah, and coal-related work in Alaska and Appalachia. The work is done both by USGS personnel and under USGS grants and contracts through the Energy Lands Program to universities, State Geological Surveys, and private individuals. Maps and reports characterizing many aspects of environmental earth science are being prepared for areas of Alaska, Montana, North Dakota, Wyoming, Utah, Colorado, New Mexico, Arizona, Oklahoma, Kansas, and Texas. Types of studies underway include bedrock, surficial, and interpretive geology; engineering geology, geochemistry of surface materials and plants; climatic conditions as they influence rehabilitation potential of mined lands; and feasibility of surface vs. underground mining. The purpose common to all investigations in the Energy Lands Program is to provide timely earth-science information for use by managers, policy-makers, engineers, scientists, planners, and others, in order to contribute to an environmentally sound, orderly, and safe development of the energy resources of the Nation.

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USGS1993

International strategic minerals inventory summary report; rare-earth oxides

Bastnaesite, monazite, and xenotime are currently the most important rare-earth minerals. Bastnaesite occurs as a primary mineral in carbonatites. Monazite and xenotime also can be found in primary deposits but are recovered principally from heavy-mineral placers that are mined for titanium or tin. Each of these minerals has a different composition of the 15 rare-earth elements. World resources of economically exploitable rare-earth oxides (REO) are estimated at 93.4 million metric tons in place, composed of 93 percent in primary deposits and 7 percent in placers. The average mineral composition is 83 percent bastnaesite, 13 percent monazite, and 4 percent of 10 other minerals. Annual global production is about 67,000 metric tons of which 41 percent is from placers and 59 percent is from primary deposits; mining methods consist of open pits (94 percent) and dredging (6 percent). This output could be doubled if the operations that do not currently recover rare earths would do so. Resources are more than sufficient to meet the demand for the predictable future. About 52 percent of the world's REO resources are located in China. Ranking of other countries is as follows: Namibia (22 percent), the United States (15 percent), Australia (6 percent), and India (3 percent); the remainder is in several other countries. Conversely, 38 percent of the production is in China, 33 percent in the United States, 12 percent in Australia, and 5 percent each in Malaysia and India. Several other countries, including Brazil, Canada, South Africa, Sri Lanka, and Thailand, make up the remainder. Markets for rare earths are mainly in the metallurgical, magnet, ceramic, electronic, chemical, and optical industries. Rare earths improve the physical and rolling properties of iron and steel and add corrosion resistance and strength to structural members at high temperatures. Samarium and neodymium are used in lightweight, powerful magnets for electric motors. Cerium and yttrium increase the density and heat resistance of sintered ceramics. Yttrium and gadolinium contribute to the efficiency of electronic switches and sensors. Cerium improves the effectiveness of catalysts in the petroleum and automotive industries. Cerium oxides speed glass melting and are used to polish glass by chemical, rather than mechanical, means. Cerium, europium, terbium, and yttrium, as phosphoric compounds, promote the vivid colors of television screens. Consumption of rare earths is expected to grow by about 2.6 percent per year.

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USGS2012

Digital recovery of 19th century surveys in Tampa Bay, Florida: Topographic charts and Public Land Surveys

Recovery of historic data to a digital setting adresses the need for data integration through time, bridging technical gaps and differences. The goal of this study was to evaluate a marsh-to-mangrove conversion spanning 125 years and the implications for present coastal-resource management (Yates and others, 2011; Raabe and others, 2012). The U.S. Geological Survey in St. Petersburg, Fla., georectified and digitized 1870s T-sheets at four Tampa Bay locations that still supported coastal wetlands in 2000 (table 1). Nineteenth century Public Land Surveys of Township and Range lines were also digitized for each site, as a secondary data source to verify historic landscape features (table 2).

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USGS2013

Natural-color and color-infrared image mosaics of the Colorado River corridor in Arizona derived from the May 2009 airborne image collection

The Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey (USGS) periodically collects airborne image data for the Colorado River corridor within Arizona (fig. 1) to allow scientists to study the impacts of Glen Canyon Dam water release on the corridor’s natural and cultural resources. These data are collected from just above Glen Canyon Dam (in Lake Powell) down to the entrance of Lake Mead, for a total distance of 450 kilometers (km) and within a 500-meter (m) swath centered on the river’s mainstem and its seven main tributaries (fig. 1). The most recent airborne data collection in 2009 acquired image data in four wavelength bands (blue, green, red, and near infrared) at a spatial resolution of 20 centimeters (cm). The image collection used the latest model of the Leica ADS40 airborne digital sensor (the SH52), which uses a single optic for all four bands and collects and stores band radiance in 12-bits. Davis (2012) reported on the performance of the SH52 sensor and on the processing steps required to produce the nearly flawless four-band image mosaic (sectioned into map tiles) for the river corridor. The final image mosaic has a total of only 3 km of surface defects in addition to some areas of cloud shadow because of persistent inclement weather during data collection. The 2009 four-band image mosaic is perhaps the best image dataset that exists for the entire Arizona part of the Colorado River. Some analyses of these image mosaics do not require the full 12-bit dynamic range or all four bands of the calibrated image database, in which atmospheric scattering (or haze) had not been removed from the four bands. To provide scientists and the general public with image products that are more useful for visual interpretation, the 12-bit image data were converted to 8-bit natural-color and color-infrared images, which also removed atmospheric scattering within each wavelength-band image. The conversion required an evaluation of the histograms of each band’s digital-number population within each map tile throughout the corridor and the determination of the digital numbers corresponding to the lower and upper one percent of the picture-element population within each map tile. Visual examination of the image tiles that were given a 1-percent stretch (whereby the lower 1- percent 12-bit digital number is assigned an 8-bit value of zero and the upper 1-percent 12-bit digital number is assigned an 8-bit value of 255) indicated that this stretch sufficiently removed atmospheric scattering, which provided improved image clarity and true natural colors for all surface materials. The lower and upper 1-percent, 12-bit digital numbers for each wavelength-band image in the image tiles exhibit erratic variations along the river corridor; the variations exhibited similar trends in both the lower and upper 1-percent digital numbers for all four wavelength-band images (figs. 2–5). The erratic variations are attributed to (1) daily variations in atmospheric water-vapor content due to monsoonal storms, (2) variations in channel water color due to variable sediment input from tributaries, and (3) variations in the amount of topographic shadows within each image tile, in which reflectance is dominated by atmospheric scattering. To make the surface colors of the stretched, 8-bit images consistent among adjacent image tiles, it was necessary to average both the lower and upper 1-percent digital values for each wavelength-band image over 20 river miles to subdue the erratic variations. The average lower and upper 1-percent digital numbers for each image tile (figs. 2–5) were used to convert the 12-bit image values to 8-bit values and the resulting 8-bit four-band images were stored as natural-color (red, green, and blue wavelength bands) and color-infrared (near-infrared, red, and green wavelength bands) images in embedded geotiff format, which can be read and used by most geographic information system (GIS) and image-processing software. The tiff world files (tfw) are provided, even though they are generally not needed for most software to read an embedded geotiff image. All image data are projected in the State Plane (SP) map projection using the central Arizona zone (202) and the North American Datum of 1983 (NAD83). The map-tile scheme used to segment the corridor image mosaic followed the standard USGS quarter-quadrangle (QQ) map borders, but the high resolution (20 cm) of the images required further quarter segmentation (QQQ) of the standard QQ tiles, where the image mosaic covered a large fraction of a QQ map tile (segmentation shown in (figure 6), where QQ_1 to QQ_4 shows the number convention used to designate a quarter of a QQ tile). To minimize the size of each image tile, each image or map tile was subset to only include that part of the tile that had image data. In addition, some QQQ image tiles within a QQ tile were combined when adjacent QQQ map tiles were small. Thus, some image tiles consist of combinations of QQQ map tiles, some consist of an entire QQ map tile, and some consist of two adjoining QQ map tiles. The final image tiles number 143, which is a large number of files to list on the Internet for both the natural-color and color-infrared images. Thus, the image tiles were placed in seven file folders based on the one-half-degree geographic boundaries within the study area (fig. 7). The map tiles in each file folder were compressed to minimize folder size for more efficient downloading. The file folders are sequentially referred to as zone 1 through zone 7, proceeding down river (fig. 7). The QQ designations of the image tiles contained within each folder or zone are shown on the index map for each respective zone (figs. 8–14).

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USGS2003

Cartographic services contract...for everything geographic

The U.S. Geological Survey's (USGS) Cartographic Services Contract (CSC) is used to award work for photogrammetric and mapping services under the umbrella of Architect-Engineer (A&E) contracting. The A&E contract is broad in scope and can accommodate any activity related to standard, nonstandard, graphic, and digital cartographic products. Services provided may include, but are not limited to, photogrammetric mapping and aerotriangulation; orthophotography; thematic mapping (for example, land characterization); analog and digital imagery applications; geographic information systems development; surveying and control acquisition, including ground-based and airborne Global Positioning System; analog and digital image manipulation, analysis, and interpretation; raster and vector map digitizing; data manipulations (for example, transformations, conversions, generalization, integration, and conflation); primary and ancillary data acquisition (for example, aerial photography, satellite imagery, multispectral, multitemporal, and hyperspectral data); image scanning and processing; metadata production, revision, and creation; and production or revision of standard USGS products defined by formal and informal specification and standards, such as those for digital line graphs, digital elevation models, digital orthophoto quadrangles, and digital raster graphics.

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USGS1999

National Wetlands Inventory products

Marshes, swamps, ponds, and bogs are teeming biological nurseries for migratory birds, fish, and aquatic plants. They also provide natural flood and erosion control. These predominantly wet areas, or wetlands as they are commonly called, now represent only about 5 percent of the land surface of the lower 48 States. Out of 221 million acres of wetlands that once existed in the conterminous United States, the U.S. Fish and Wildlife Service (FWS) estimates that only about 103.3 million acres remain. Each year, development, drainage, and agriculture eliminate another 290,000 acres - an area a little less than half the size of Rhode Island. From the 1950's to the 1970's, conversion of wetlands to farmland caused 87 percent of all wetland losses. The FWS has long recognized the importance of America's wetlands because they form breeding and wintering grounds for great numbers of migratory birds. In 1977, the FWS began the National Wetlands Inventory (NWI), a systematic effort to classify and map America's remaining wetlands.

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USGS1998

National Wetlands Inventory products

Marshes, swamps, ponds, and bogs are teeming biological nurseries for migratory birds, fish, and aquatic plants. They also provide natural flood and erosion control. These predominantly wet areas, or wetlands as they are commonly called, now represent only about 5 percent of the land surface of the lower 48 States. Out of 221 million acres of wetlands that once existed in the conterminous United States, the U.S. Fish and Wildlife Service (FWS) estimates that only about 103.3 million acres remain. Each year, development, drainage, and agriculture eliminate another 290,000 acres-an area a little less than half the size of Rhode Island. From the 1950's to the 1970's, conversion of wetlands to farmland caused 87 percent of all wetland losses. The FWS has long recognized the importance of America's wetlands because they form breeding and wintering grounds for great numbers of migratory birds. In 1977, the FWS began the National Wetlands Inventory (NWI), a systematic effort to classify and map America's remaining wetlands.

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USGS2006

Pesticides in Ground Water of the Maryland Coastal Plain

Selected pesticides are detectable at low levels (generally less than 0.1 microgram per liter) in unconfined ground water in many parts of the Maryland Coastal Plain. Samples were recently collected (2001-04) from 47 wells in the Coastal Plain and analyzed for selected pesticides and degradate compounds (products of pesticide degradation). Most pesticide degradation occurs in the soil zone before infiltration to the water table, and degradates of selected pesticides were commonly detected in ground water, often at higher concentrations than their respective parent compounds. Pesticides and their degradates often occur in ground water in mixtures of multiple compounds, reflecting similar patterns in usage. All measured concentrations in ground water were below established standards for drinking water, and nearly all were below other health-based guidelines. Although drinking-water standards and guidelines are typically much higher than observed concentrations in ground water, they do not exist for many detected compounds (particularly degradates), or for mixtures of multiple compounds. The distribution of observed pesticide compounds reflects known usage patterns, as well as chemical properties and environmental factors that affect the fate and transport of these compounds in the environment. Many commonly used pesticides, such as glyphosate, pendimethalin, and 2,4-D were not detected in ground water, likely because they were sorbed onto organic matter or degraded in the soil zone. Others that are more soluble and (or) persistent, like atrazine, metolachlor, and several of their degradates, were commonly detected in ground water where they have been used. Atrazine, for example, an herbicide used primarily on corn, was most commonly detected in ground water on the Eastern Shore (where agriculture is common), particularly where soils are well drained. Conversely, dieldrin, an insecticide previously used heavily for termite control, was detected only on the Western Shore, where urban land is more common. Use of dieldrin was suspended in 1987, but this compound is relatively persistent in the environment, and several decades are typically required for ground water to move completely through the surficial aquifer. U.S. Department of the Interior U.S. Geological Survey USGS Fact Sheet FS 2006-3119 2006 Location of the Maryland Coastal Plain.

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USGS2011

Vegetation recovery after fire in the Klamath-Siskiyou region, southern Oregon

In July 2002, lightning strikes started five forest fires that merged into one massive wildfire in the Klamath-Siskiyou Ecoregion of southern Oregon. Aided by drought, severe weather conditions, dry fuels, and steep topography, the fire grew to more than 200,000 hectares of mostly public forest land. Known as the Biscuit Fire, it was Oregon's largest forest fire in more than 130 years and one of the largest wildfires on record in the United States. Discussions centered around why such a massive fire was happening, how large would it become, who was keeping communities and homes safe, and what would be the final economic and ecological outcome. Weeks later when the fire was out, conversations turned to other questions, including what, if anything, should happen for forest recovery.

Oregon↗