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At least 1,441 records · Page 80Linked to original sources
USGS2004

Landsat yesterday and today: An American vision and an old challenge

Since the late 1960s, the United States government has invested more than $1 billion in designing, launching, and operating the Landsat (land satellite) series of Earth-observing satellites. Global change researchers, geologists, and environmental scientists have used images gathered by the satellites for purposes ranging from human health research, energy exploration, and pollution detection to agricultural assessments, urban growth monitoring, and earthquake lineament studies. The earliest data were captured on a digital medium called wide-band video tape (WBVT). However, two decades of unsound media storage conditions and a poorly maintained processing system have left the physically deteriorating WBVTs with no mechanism for interpretation. A national treasure was in jeopardy. With seed money from the National Aeronautics and Space Administration (NASA), the U.S. Geological Survey (USGS) began a project to rescue the data. More than 21,000 tapes from the 1970s have been transcribed to stable, archival media, preserving the data for future studies in Earth System Science.

Journal of Map & Geography Libraries↗
USGS2006

High-resolution stratigraphy of a Mississippi subdelta-lobe progradation in the Barataria Bight, north-central Gulf of Mexico

The coastal zone of southeastern Louisiana is the product of numerous cycles of progradation, abandonment, and marine transgression of the Mississippi River delta. Currently, the shoreline in the Barataria Bight is undergoing significant erosion and retreat, and understanding its evolution is crucial in stabilization efforts. This study uses an extensive collection of geophysical and sediment core data from Barataria Bay and offshore to develop a geologic model of the shallow (< 10 m) subsurface. The purpose of the model is twofold: (1) establish the stratigraphic architecture of a subdelta lobe of the Bayou des Families delta, deposited by the Mississippi River approximately 4000 years before present; and (2) provide a high-resolution description of the geologic framework in a context that can be applied to coastal management issues in similar fluvially dominated coastal environments worldwide. The results of the study demonstrate how high-quality geologic data from the coastal environment can be used not only to further our understanding of shoreline evolution but also to provide pertinent information for coastal management needs.

Louisiana↗
USGS1987

The hydrothermal system of the Calabozos caldera, central Chilean Andes

Active thermal springs associated with the late Pleistocene Calabozos caldera complex occur in two groups: the Colorado group which issues along structures related to caldera collapse and resurgence, and the Puesto Calabozos group, a nearby cluster that is chemically distinct and probably unrelated to the Colorado springs. Most of the Colorado group can be related to a hypothetical parent water containing ???400 ppm Cl at ???250??C by dilution with ???50% of cold meteoric water. The thermal springs in the most deeply eroded part of the caldera were derived from the same parent water by boiling. The hydrothermal system has probably been active for at least as long as 300,000 years, based on geologic evidence and calculations of paleo-heat flow. There is no evidence for economic mineralization at shallow depth. The Calabozos hydrothermal system would be an attractive geothermal prospect were its location not so remote. ?? 1987.

Journal of Volcanology and Geothermal Research↗
USGS2008

Water Use in Florida, 2005 and Trends 1950-2005

Water is among Florida's most valued resources. The State has more than 1,700 streams and rivers, 7,800 freshwater lakes, 700 springs, 11 million acres of wetlands, and underlying aquifers yielding quantities of freshwater necessary for both human and environmental needs (Fernald and Purdum, 1998). Although renewable, these water resources are finite, and continued growth in population, tourism, and agriculture will place increased demands on these water supplies. The permanent population of Florida in 2005 totaled 17.9 million, ranking fourth in the Nation (University of Florida, 2006); nearly 86 million tourists visited the State (Orlando Business Journal, 2006). In 2005, Florida harvested two-thirds of the total citrus production in the United States and ranked fifth in the Nation net farm income (Florida Department of Agriculture and Consumer Services, 2006). Freshwater is vital for sustaining Florida's population, economy, and agricultural production. Accurate estimates reflecting water use and trends in Florida are compiled in 5-year intervals by the U.S. Geological Survey (USGS) in cooperation with the Florida Department of Environmental Protection (FDEP) and the Northwest Florida, St. Johns River, South Florida, Southwest Florida, and Suwannee River Water Management Districts (Marella, 2004). This coordinated effort provides the necessary data and information for planning future water needs and resource management. The purpose of this fact sheet is to present the highlights of water use in Florida for 2005 along with some significant trends in withdrawals since 1950.

Fact Sheet↗
USGS2008

High Resolution Imaging Science Experiment (HiRISE) observations of glacial and periglacial morphologies in the circum-Argyre Planitia highlands, Mars

The landscape of the Argyre Planitia and adjoining Charitum and Nereidum Montes in the southern hemisphere of Mars has been heavily modified since formation of the Argyre impact basin. This study examines morphologies in the Argyre region revealed in images acquired by the High Resolution Imaging Science Experiment (HiRISE) camera and discusses the implications for glacial and periglacial processes. Distinctive features such as large grooves, semicircular embayments in high topography, and streamlined hills are interpreted as glacially eroded grooves, cirques, and whalebacks or roche moutonnée, respectively. Large boulders scattered across the floor of a valley may be ground moraine deposited by ice ablation. Glacial interpretations are supported by the association of these features with other landforms typical of glaciated landscapes such as broad valleys with parabolic cross sections and stepped longitudinal profiles, lobate debris aprons interpreted as remnant debris covered glaciers or rock glaciers, and possible hanging valleys. Aligned boulders observed on slopes may also indicate glacial processes such as fluting. Alternatively, boulders aligned on slopes and organized in clumps and polygonal patterns on flatter surfaces may indicate periglacial processes, perhaps postglaciation, that form patterned ground. At least portions of the Argyre region appear to have been modified by processes of ice accumulation, glacial flow, erosion, sediment deposition, ice stagnation and ablation, and perhaps subsequent periglacial processes. The type of bedrock erosion apparent in images suggests that glaciers were, at times, wet based. The number of superposed craters is consistent with geologically recent glacial activity, but may be due to subsequent modification.

Journal of Geophysical Research E: Planets↗
USGS2023

The usability gap in water resources open data and actionable science initiatives

The open data movement represents a major advancement for informed water management. Data that are findable, accessible, interoperable, and reusable—or FAIR —are now prerequisite to responsible data stewardship. In contrast to FAIR, accessibility and usability case studies and guidelines designed around human access and understanding are lacking in the literature, especially for water resources. Such decision support guidelines are critical because (i) inherent visual design trade-offs are not best made using intuition or feedback (perceived preference), and (ii) choosing designs requires a nuanced understanding of why and how the design works (revealed effectiveness). Thus, the goal of this commentary is to highlight knowledge gaps and discuss a general usability testing method which can be applied to any water resources decision support product. The user-testing approach includes (i) interviews about visualization goals, audiences, and the uses and decisions made with the data products, (ii) diagnosis of usability challenges, and (iii) redesign of decision support products given best practices and control versus treatment with intended end-user audiences. We illustrate the method using high-profile U.S. Geological Survey water science products. In sum, optimizing and testing for usability and understandability are as central to stakeholder use as FAIR standards are, and warrant being part of the development of data products and geovisualizations.

Journal of the American Water Resources Associatio↗
USGS1998

Military geology unit of the U.S. Geological Survey during World War II

On June 24, 1942, the temporary Military Geology Unit of the U.S. Geological Survey was formalized after the U.S. Army Corps of Engineers requested them to prepare terrain intelligence studies to meet wartime priorities. The entire Military Geology Unit wartime roster was 114 professionals, including 88 geologists, 11 soil scientists, and 15 other specialists; 14 were women. Assisting staff (illustrators, typists, photographers, and others) totaled 43. The unit produced 313 studies, including 140 major terrain folios, 42 other major special reports, and 131 minor studies. These reports contain about 5,000 maps, 4,000 photographs and figures, 2,500 large tables, and 140 terrain diagrams. Most products were designed in the beginning for general strategic planning in Washington and later for detailed strategic planning overseas; they utilized graphics and nontechnical, telegraphic-style tabular texts. The Military Geology Unit's principal effort was the preparation of the terrain folios titled Strategic Engineering Studies. They varied somewhat in content and format, but the key components usually were introduction, terrain appreciation, rivers, road and airfield construction, construction materials, and water resources. The folios, produced at an average rate of about one per week and at an average cost of $2,500, were compiled from scientific journals, books, maps, and photographs available in the Washington area by a team of 3 to 8 scientists; 8 to 12 teams might be working concurrently. MGU personnel took great pride in never having missed a delivery deadline.

Book chapter↗
USGS2015

Assessing the geologic and climatic forcing of biodiversity and evolution surrounding the Gulf of California

For almost a century the Baja California peninsula (Peninsula), Gulf of California (Gulf), and broader Sonoran Desert region (figure 1) have drawn geologists and biologists alike to study its unique physical and evolutionary processes (e.g., Wittich 1920; Darton 1921; Nelson 1921; Johnston 1924; Beal 1948; Durham and Allison 1960). The challenge remains to untangle the long, intricate, and at times enigmatic geological and climatological histories that have shaped the high levels of endemism and biodiversity observed in the region today (Van Devender 1990; Grismer 2000; Riddle et al. 2000).

Gulf of California↗
USGS2015

Book review: Rare earth elements—A new approach to the nexus of supply, demand and use: exemplified along the use of neodymium in permanent magnets

This book is part of the &ldquo;Springer Theses&rdquo; published by Springer, a book series designed to highlight and share outstanding Ph.D. research. As explained by Springer (on the second page), this series &ldquo;brings together a selection of the very best Ph.D. theses from around the world and across the physical sciences.&rdquo; I admire Springer for this endeavor because a large number of exceptional theses are never published, and thus are difficult to obtain, while most of those that are published are presented only in highly condensed form as journal articles. Review info: Rare Earth Elements&mdash;A New Approach to the Nexus of Supply, Demand and Use: Exemplified Along the Use of Neodymium in Permanent Magnets . By Volker Zerf. 2013. ISBN 978-3-642-35457-1. 157 pp.

Economic Geology↗
USGS2001

Factors controlling the configuration of the fresh-saline water interface in the Dead Sea coastal aquifers: Synthesis of TDEM surveys and numerical groundwater modeling

TDEM (time domain electromagnetic) traverses in the Dead Sea (DS) coastal aquifer help to delineate the configuration of the interrelated fresh-water and brine bodies and the interface in between. A good linear correlation exists between the logarithm of TDEM resistivity and the chloride concentration of groundwater, mostly in the higher salinity range, close to that of the DS brine. In this range, salinity is the most important factor controlling resistivity. The configuration of the fresh-saline water interface is dictated by the hydraulic gradient, which is controlled by a number of hydrological factors. Three types of irregularities in the configuration of fresh-water and saline-water bodies were observed in the study area: 1. Fresh-water aquifers underlying more saline ones ("Reversal") in a multi-aquifer system. 2. "Reversal" and irregular residual saline-water bodies related to historical, frequently fluctuating DS base level and respective interfaces, which have not undergone complete flushing. A rough estimate of flushing rates may be obtained based on knowledge of the above fluctuations. The occurrence of salt beds is also a factor affecting the interface configuration. 3. The interface steepens towards and adjacent to the DS Rift fault zone. Simulation analysis with a numerical, variable-density flow model, using the US Geological Survey's SUTRA code, indicates that interface steep- ening may result from a steep water-level gradient across the zone, possibly due to a low hydraulic conductivity in the immediate vicinity of the fault.

Hydrogeology Journal↗
USGS1969

Hydrology of carbonate rock terranes — A review: With special reference to the United States

Limestone and other carbonate rocks are characterized by many unusual features and extreme conditions, either involving the hydrologic system within them or wrought by hydrologic conditions on them or through them. Perhaps there could be little agreement as to what is typical or average for the many features of carbonate rocks, as indicated by the following conditions: bare rock and thin soils are common, but so are thick soils; very highly permeable limestones are common, but so are poorly permeable ones; and rugged karst topographic features with underlying solution caverns are common, but so are flat, nearly featureless topographic conditions. Some conditions of carbonate terranes are suitable to man's needs and interests, such as the use of some permeable aquifers for water supply and the exploitation of caves for tourist attractions. On the other hand, many problems may exist, including: permeability too low for adequate water supply or so high that the aquifer retains too little water for use during periods of fair weather, soils too thin for growing of crops and for adequate filtration of wastes near the ground surface, instability of the ground for buildings and foundations in sinkhole areas, and unusually rugged topography. Some of the many variable conditions are readily observable, but others can be determined only by careful geologic and hydrologic studies. The need for knowing the specific geologic and hydrologic conditions at various places in limestone terranes, as well as the variations in hydrologic conditions with changing conditions and time, has resulted in many published reports on local areas and on special topical problems of limestone hydrology. Many of these reports have been used to advantage by the present writers in preparing this paper. The concept that secondary permeability is developed by circulation of water through openings with the accompanying enlargement of these openings by solution is now universally accepted in limestone terranes. Emphasis is placed on the hydrogeologic framework, or structural setting, in relation to the ease or difficulty of water to move from a source of recharge, through a part of the limestone, to a discharge area. Parts of the limestone favored by circulating ground water tend to develop solution openings, commonly in the upper part of the zone of saturation; as base level is lowered (sea level or perennial stream level), the related water table lowers in the limestone leaving air-filled caverns above the present zone of saturation in sinkhole areas. Reconstruction of the geologic and hydrologic history of a limestone area aids in determining the extent of development and the positions of fossil and present permeability. References are made to the hydrology of many limestone regions, especially those of the United States.

Journal of Hydrology↗
USGS2019

Estimating the pressure-limited dynamic capacity and costs of basin-scale CO2 storage in a Saline Formation

Deployment of carbon capture and storage (CCS) could be necessary to be able to satisfy baseload electricity demand, maintain diversity in the energy mix, and achieve mitigation of carbon dioxide (CO 2 ) emissions at lowest cost ( IPCC, 2015 ; U.S. DOE, 2016 ). If basin-, regional- or national-scale deployment of CCS is needed, it may be possible to store only a small fraction of the captured CO 2 in oil and natural gas reservoirs. The vast majority would likely have to be stored in saline formations. Pressure buildup as a result of injecting CO 2 into such reservoirs is expected to be an important source of risk associated with CO 2 storage, and could constrain dynamic storage capacities (maximum injection rates) to be far below estimates based on access to theoretical storage resources. Estimates of CO 2 storage costs based on an assumption of practical availability of the theoretical storage resource could lead to underestimation of the costs of CO 2 storage. In this study, simulation results suggest that the pressure-limited dynamic CO 2 storage capacity of the Mount Simon Sandstone could be less than 4% of the theoretical storage resource in this saline formation, and storage costs could be an order of magnitude higher than recent estimates. However, consideration of the geologic heterogeneity in this deep saline formation allowed definition of a high injectivity zone, and estimated costs of CO 2 storage in this “sweet spot” of the reservoir approached recent estimates that did not include costs for pressure management.

Illinois, Indiana, Kentucky↗
USGS2012

Compaction of basin sediments: Modeling based on time-temperature history

Porosity decrease of sandstones, carbonates, and shales during burial is modeled here in terms of time-temperature exposure rather than in terms of depth. Loss of porosity (ϕ) in the subsurface is represented by a power function, ϕ = A ( M ) B , where A and B are constants and M is a measure of integrated time-temperature history. Regression lines of carbonate and sandstone porosity upon Lopatin's time-temperature index of thermal maturity (TTI) generally fall within a rather narrow envelope whose axis is approximated by ϕ = 30(TTI) −0.33 . This equation is useful for regional modeling of carbonate and sandstone compaction. Dependence of porosity upon integrated time-temperature history implies that basin sediments are not in equilibrium but compact through geologic time. Calculations show that subsidence resulting from the loss of porosity with increasing time-temperature exposure (as opposed to deeper burial) can produce a second-stage, passively formed basin containing many hundreds of meters of sediments.

Journal of Geophysical Research Solid Earth↗
USGS1997

On the origin of diverse aftershock mechanisms following the 1989 Loma Prieta earthquake

We test the hypothesis that the origin at the diverse suite of aftershock mechanisms Following the 1989 M 7.1 Loma Prieta, California, earthquake is related to the post-main-shock static stress field We use a 3-D boundary-element algorithm to calculate static stresses combined with a Coulomb failure criterion to calculate conjugate failure planes at aftershock locations. The post-main-shock static stress field is taken as the of a sum of a pre-existing stress field and changes in stress due to the heterogeneous slip across the Loma Prieta rupture plane. The background stress field is assumed to be either a simple shear parallel to the regional trend of the San Andreas fault or approximately fault-normal compression A suite of synthetic aftershock mechanisms from the conjugate failure planes is generated and quantitatively compared (allowing for uncertainties in both mechanism parameters and earthquake locations) to well-constrained mechanisms reported in the US Geological Survey Northern California Seismic Network catalogue. We also compare calculated rakes with those observed by resolving the calculated stress tensor onto observed focal mechanism nodal planes, assuming either plane to be a likely rupture plane.

Geophysical Journal International↗
USGS1998

Mapping the Gulf of Maine with side-scan sonar: A new bottom-type classification for complex seafloors

The bedrock-framed seafloor in the northwestern Gulf of Maine is characterized by extreme changes in bathymetric relief and covered with a wide variety of surficial materials. Traditional methods of mapping cannot accurately represent the great heterogeneity of such a glaciated region. A new mapping scheme for complex seafloors, based primarily on the interpretation of side-scan sonar imagery, utilizes four easily recognized units: rock, gravel, sand and mud. In many places, however, the seafloor exhibits a complicated mixture or extremely 'patchy' distribution of the four basic units, which are too small to map individually. Twelve composite units, each a two-component mixture of the basic units, were established to represent this patchiness at a small scale (1:100,000). Using a geographic information system, these and all other available data (seismic profiles, grab samples, submersible dives and cores) were referenced to a common geographic base, superimposed on bathymetric contours and then integrated into surficial geologic maps of the regional inner continental shelf. This digital representation of the seafloor comprises a multidimensional, interactive model complete with explicit attributes (depth, bottom type) that allow for detailed analysis of marine environments.

Journal of Coastal Research↗
USGS1994

Bibliography of The World Energy Resources Program

The following publications were prepared in the course of World Energy Studies by program scientists. Most are open-file reports because we consider it our prime responsibility to get the program supporting data into the public record. Various of the authors have also seen fit to publish their work in refereed scientific journals and those publication outlets are also listed. The summation of the program work is reported in the proceedings volumes of the World Petroleum Congresses-see Global section of the bibliography. In those reports, petroleum resource data were aggregated by major petroleum resource countries. It is our intention to ultimately report resource data by petroleum basin in order to provide a closer tie of resource understanding and petroleum geology.

Open-File Report↗
USGS1981

Geological considerations in hazardous waste disposal

Present regulations assume that long-term isolation of hazardous wastes - including toxic chemical, biological, radioactive, flammable and explosive wastes - may be effected by disposal in landfills that have liners of very low hydraulic conductivity. In reality, total isolation of wastes in humid areas is not possible; some migration of leachate from wastes buried in the gound will always occur. Regulations should provide performance standards applicable on a site-by-site basis rather than rigid criteria for site selection and design. The performance standards should take into account several factors: (1) the categories, segregation, degradation and toxicity of the wastes; (2) the site hydrogeology, which governs the direction and rate of contaminant transport; (3) the attenuation of contaminants by geochemical interactions with geologic materials; and (4) the release rate of unattenuated pollutants to surface or groundwater. An adequate monitoring system is essential. The system should both test the extent to which the operation of the site meets performance standards and provide sufficient warning of pollution problems to allow implementation of remedial measures. In recent years there has been a trend away from numerous, small disposal sites toward fewer and larger sites. The size of a disposal site should be based on the attenuation capacity of the geologic material, which has a finite, though generally not well-defined, limit. For slowly degradable wastes, engineered sites with leachate-collection systems appear to be only a temporary solution since the leachate collected will also require final disposal.

Journal of Hydrology↗