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In 1982 and 1984 the U.S. Geological Survey used several seismic networks, totaling over 90 stations, to record teleseismic P waves and measure travel time residuals in an area centered on the Long Valley caldera. We inverted the travel time residuals to obtain a three-dimensional image of the velocity structure with resolution...

Theory, laboratory experiments, and empirical observation suggest that many aqueous fluid inclusions in calcite reequilibrate during overheating, and therefore some homogenization temperatures (Th) record a temperature close to the maximum reached by the rock. This characteristic suggests that aqueous fluid inclusions in calcite can be used to establish maximum temperature...

Equations are developed for predicting the liquid-film and gas-film reference-substance parameters for quantifying volatilization of organic solutes from streams. Molecular weight and molecular-diffusion coefficients of the solute are used as correlating parameters. Equations for predicting molecular-diffusion coefficients of organic solutes in water and air are developed, with molecular weight and...

Three methods have been used to produce high-density volatiles in the system C-O-H-N for the calibration of a laser Raman microprobe (LRM): synthetic fluid-inclusion, sealed fused-quartz-tube, and high-pressure-cell methods. Because quantitative interpretation of a Raman spectrum of mixed-volatile fluid inclusions requires accurate knowledge of pressure- and composition-sensitive Raman scattering efficiencies...

In assessing the errors involved in reconstructing tectonic plate rotations, it is desirable to have confidence regions for the unknown rotation. This paper presents a method for graphing such confidence regions, which exhibits the dependence of the range of possible angles of rotation on the axis considered. Namely, the minimum...

A rapid, specific and highly sensitive method is described for the determination of several commonly used herbicides and their degradation products in surface and ground waters by using gas chromatography/ion-trap mass spectrometry. The compounds included atrazine, and its degradation products desethylatrazine and desisopropylatrazine; Simazine; Cyanazine; Metolachlor; and alachlor and its...

Estimation of layer parameters such as interval velocity, reflector depth, and dip can be formulated as a generalized linear inverse problem using observed arrival times. Based on a 2-D earth model, a computationally efficient and accurate formula is derived for traveltime inversion. This inversion method is applied to offset vertical...

A combination of a highly accurate bathymetric surveying technique and in-situ submersible observations and measurements were used to assess the migrational trends and morphological changes of large sand waves (Ht ≤ 17 m) in eastern Long Island Sound. Although residing in a high-energy tidal environment characterized...

The precision and continuity of data recorded by unmanned digital magnetic observatories depend on the type of data acquisition equipment used and operating procedures employed. Three generations of observatory systems used by the U.S. Geological Survey are described. A table listing the frequency of component failures in the current observatory...

Lateral channel change on the mainly ephemeral Santa Cruz River, Pima County, Arizona, causes damage and has spawned costly efforts to control bank erosion. Aerial photographs, historical data, and field observations are used to document the history of channel change since 1936. Variability in the nature and degree of channel...

X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. Trace elements (Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, La, and Ce) in coal ash were determined by energy-dispersive X-ray fluorescence spectrometry; major elements (Na, Mg, Al, Si, P, S, K, Ca,...

A comparison is made of geomagnetic calibration data obtained from a high-sensitivity proton magnetometer enclosed within an orthogonal bias coil system, with data obtained from standard procedures at a mid-latitude U.S. Geological Survey magnetic observatory using a quartz horizontal magnetometer, a Ruska magnetometer, and a total field magnetometer. The orthogonal...

Impulse responses including near-field terms have been obtained in closed form for the zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an anelastic half-space. The method is based on the correspondence principle. Through transformation of variables, the Fourier transform of the elastic impulse...

Joint research by the U.S. Geological Survey and the University of Missouri-Rolla currently (1990) is being conducted on a 3.05 meters in diameter vertically rotating flume used to simulate mudflows under steady-state conditions. Observed mudflow simulations indicate flow patterns in the flume are similar to those occurring in natural mudflows....

Measurements of currents, waves and light transmission obtained with an instrumented bottom tripod (GEOPROBE) were used in conjunction with a theoretical bottom-boundary-layer model for waves and currents to investigate sediment transport on the continental shelf south of the Ebro River Delta,...

Extracting subtle differences from highly correlated thermal infrared aircraft data is possible with appropriate noise filters, constructed and applied in the spatial frequency domain. This paper discusses a heuristic approach to designing noise filters for removing high- and low-spatial frequency striping and banding. Techniques for registering thermal infrared aircraft data...

87Sr 86Sr ratios, trace element and REE compositions, and textural characteristics were determined for three hydrogenetic Fe-Mn crusts, one hydrothermal deposit, and two mixed hydrothermalhydrogenetic crusts from the Pacific. The Sr isotope data are compared to the Sr seawater curve for the Cenozoic to determine the ages and growth rates...

Ground resolution requirements for detection and extraction of road locations in a digitized large-scale photographic database were investigated. A color infrared photograph of Sunnyvale, California was scanned, registered to a map grid, and spatially degraded to 1- to 5-metre resolution pixels. Road locations in each data set were extracted using...

A field-scale soil linear was built to assess the feasibilty of constructing a liner to meet the saturated hydraulic conductivity requirement of the U.S. EPA (i.e., less than 1 ?? 10-7 cm/s), and to determine the breakthrough and transit times of water and tracers through the liner. The liner, 8...

The accumulation kinetics of two waterborne polycyclic aromatic hydrocarbons (PAHs), benzo[a]pyrene (BAP) and phenanthrene (PHE), were studied in the mayfly nymph (Hexagenia limbata). The uptake clearance decreased while the bioconcentration of BAP increased with an increase in weight of the H. limbata nymph. The relationship between uptake clearance and bioconcentration for PHE was...

In an effort to determine the in situ production rate of spallation-produced cosmogenic 3He, and evaluate its use as a surface exposure chronometer, we have measured cosmogenic helium contents in a suite of Hawaiian radiocarbon-dated lava flows. The lava flows, ranging in age...

The kinetics of accumulation of pentachlorophenol (PCP) at various pH values were investigated to explore how pH-dependent accumulation might influence PCP toxicity. Goldfish (Carassius auratus) were exposed to 5 μg PCP/L in a static system buffered with 7.5 mM bicine orN,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (BES) at pH 7.0, 8.0, or 9.0....

This study was initiated to investigate the impacts of geothermal development in the Corwin Springs Known Geothermal Resources Area (KGRA) on the hydrothermal features of Yellowstone National Park. To determine possible hydrogeochemical connections, we used the diagnostic stable and radioactive isotopes of several elements, and the chemical and gas compositions...

Abstract not supplied at this time...

Grade-tonnage models are frequency distributions of deposit tonnage and grades of mineral deposits of a specific type. The program described here allows users to prepare standard figures of grade and tonnage distributions and display the deposit name associated with any of the data points. Titles and scales appropriate for most...