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At least 1,513 records · Page 84Linked to original sources

MAJOR SOURCE OF SIDE-LOOKING AIRBORNE RADAR IMAGERY FOR RESEARCH AND EXPLORATION: THE U. S. GEOLOGICAL SURVEY.

The US Geological Survey (USGS) instituted a program in 1980 to acquire side-looking airbore radar (SLAR) data and make these data readily available to the public in a mosaic format comparable to the USGS 1:250,000-scale topographic map series. The SLAR data are also available as strip images at an acquisition scale of 1:250,000 or 1:400,000 (depending on the acquisition system), as a variety of print products and indexes, and in a limited amount in digital form on computer compatible tapes. Three different commercial X-band (3-cm) systems were used to acquire the imagery for producing the mosaics.

Conference Paper↗

THREE-COMPONENT BOREHOLE MAGNETOMETER PROBE FOR MINERAL INVESTIGATIONS AND GEOLOGIC RESEARCH.

A small-diameter three-component fluxgate magnetometer probe with gyroscopic and inclinometer orientation has been developed to meet U. S. Geological Survey design and performance specifications for measurement of the direction and intensity of the Earth's magnetic field in vertical and inclined boreholes. The orthogonal fluxgate magnetometer elements have a measurement resolution of 10 nanoteslas (nT) and a range of plus or minus 80,000 nT. The gyroscope has an effective resolution of one degree, and the orthogonal inclinometers, 0. 1 degree. The magnetometer probe has been field tested in several holes drilled through volcanic rocks in Nevada. Results indicate that reversals of polarization can be detected, and some rock units in this area appear to be characterized by unique magnetic signatures.

Conference Paper↗

U. S. GEOLOGICAL SURVEY'S RESEARCH PROGRAM IN THE NEWLY PROCLAIMED EXCLUSIVE ECONOMIC ZONE.

The U. S. Geological Survey (USGS) has been developing a program which would emphasize broad-scale surveys of the continental margin and intensive studies of 'baseline corridors' in various areas of the U. S. EEZ to gather energy and mining information in this new frontier as quickly as possible. Of twelve baseline corridors identified to date along the east and west coasts and the Gulf of Mexico, the highest priority would be placed on areas off the west coast, including Juan De Fuca and Gorda Ridges and off Hawaii. Each corridor assessment will involve collection of multi-channel and high resolution geophysical data, bottom relief and sampling, and production of reports and cartographic products displaying the scientific findings of the assessments.

Conference Paper↗

Seismically induced landslides: current research by the US Geological Survey.

We have produced a regional seismic slope-stability map and a probabilistic prediction of landslide distribution from a postulated earthquake. For liquefaction-induced landslides, in situ measurements of seismically induced pore-water pressures have been used to establish an elastic model of pore pressure generation. -from Authors

Geologia Applicata e Idrogeologia↗

Loss of coastal wetlands in Louisiana: Cooperative research to assess the critical processes

Erosion of the nation's shoreline and loss and deterioration of our coastal wetlands are widespread and serious problems that affect all regions of the US. As a result of natural and human-induced factors, the coastal plain of Louisiana, which contains 40% of the tidal wetlands in the conterminous 48 States, is undergoing the greatest amount of coastal erosion and wetlands loss in the nation. The barrier islands that provide a natural buffer for Louisiana's deltaic plain environments are experiencing erosion rates of 20m/yr, while wetlands losses are about 100km2/yr. In response to these problems and the lack of scientific understanding of the processes causing erosion and land loss, the US Geological Survey has, since 1986, conducted field investigations in Louisiana, working closely with the US Fish and Wildlife Service and other Federal and State agencies.

Biological Report - US Fish & Wildlife Service↗

Taming a wild geothermal research well in yellowstone national park

In November 1992 the valve at the top of a U.S. Geological Survey drill hole in Yellowstone National Park parted from the casting as a result of corrosion. This allowed uncontrolled venting of boiling water and steam from the well at an estimated liquid flow rate of about 25-50 gallons per minute. A flow diverter assembly was designed, fabricated and installed on the well within 16 days, which allowed drill rods to be safely stripped into the well through on annular Blow-Out Preventer. Once this was accomplished it was a relatively routine matter to set a packer in the casting and cement the well shut permanently. The drill hole was brought under control and cemented shut within 18 days of the wellhead failure at a total cost of $47,066, which was about $5,000 less than anticipated.

Conference Paper↗

Relation between gas hydrate and physical properties at the Mallik 2L-38 research well in the Mackenzie delta

As part of an interdisciplinary field program, a 1150-m deep well was drilled in the Canadian Arctic to determine, among other goals, the location, characteristics, and properties of gas hydrate. Numerous physical properties of the host sediment were measured in the laboratory and are presented in relation to the lithology and quantity of in situ gas hydrate. Profiles of measured and derived properties presented from that investigation include: sediment wet bulk density, water content, porosity, grain density, salinity, gas hydrate content (percent occupancy of non-sediment grain void space), grain size, porosity, and post-recovery core temperature. The greatest concentration of gas hydrate is located within sand and gravel deposits between 897 and 922 m. Silty sediment between 926 and 952 m contained substantially less, or no, gas hydrate perhaps because of smaller pore size.

Conference Paper↗

Research on genesis of pyrite near the Permian-Triassic boundary in meishan, Zhejiang, China

The content and crystal forms of pyrite and sulfur isotope composition of pyrite sulfur as well as its vertical distribution near the Permian-Triassic (P/T) boundary in the Meishan section, Changxing county, Zhejiang province, China were studied using geological, petrological, mineralogical and geochemical methods (techniques). The result showed that the genesis of abundant pyrites in bed 24e2 at the uppermost part of the Changxing Formation in the Meishan section may be related to volcanic activity. In bed 24e2 of the Meishan section, pyrite has its highest content of 1.84% and the sulfur isotope composition has the highest ??34S value at + 2.2??? which is very similar to that of the average value of volcanic gas. There are some volcanic products such as ??-quartz, siliceous cylinders and siliceous spherules which coexisted with pyrites in beds 24e2 and 24f. It can be concluded that a large quantity of volcanic ash fell into the South China Sea and was incorporated into marine sediments during the formation of limestone at the uppermost part of the Changxing Formation. The volcanic eruption with massive amounts of H2S and S02 gas at the end of the Permian period resulted in the enrichment of H2S in the South China Sea areas. The reaction of H2S with reactive iron minerals formed the mass of abundant pyrites.

Journal of China University of Mining and Technolo↗

The Colorado Plateau V: research, environmental planning, and management for collaborative conservation

Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions.This volume, the fifth from the University of Arizona Press and the tenth overall, focuses on adaptation of resource management and conservation to climate change and water scarcity, protecting biodiversity through restructured energy policies, ensuring wildlife habitat connectivity across barriers, building effective conservation networks, and exploring new opportunities for education and leadership in conservation science.An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

Book↗