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A complex sequence of pyroclastic flows and surges erupted by Nevado del Ruiz volcano on 13 November 1985 interacted with snow and ice on the summit ice cap to trigger catastrophic lahars (volcanic debris flows), which killed more than 23,000 people living at or beyond the base of the volcano....

Depositional patterns and sedimentary processes influencing modern southwest Florida carbonate slope development have been identified based upon slope morphology, seismic facies and surface sediment characteristics. Three slope-parallel zones have been identified: (1) an upper slope progradational zone (100–500 m) characterized by...

Aquatic communities in the Boise River were examined from October 1987 to March 1988 to determine whether they were adversely affected by trace elements in effluents from two Boise wastewater treatment facilities. Trace-element concentrations in the Boise River were less than or near analytical-detection levels and were less than chronic...

A rock cylinder, containing a clay-filled sawcut making an angle of 30?? to the sample axis, was deformed at constant confining and pore pressures and constant remote shortening rate. The sawcut surfaces contained a series of regularly spaced ridges and grooves oriented perpendicular to the direction of shear. The interaction...

Tangkuban Parahu is an active stratovolcano located 17 km north of the city of Bandung in the province west Java, Indonesia. All historical eruptive activity at this volcano has been confined to a complex of explosive summit craters. About a dozen eruptions-mostly phreatic events- and 15 other periods of unrest,...

In the early 1980's, renewed interest in the geothermal potential of the Long Valley caldera, California, highlighted the need to balance the benefits of energy development with the established recreational activities of the area. The Long Valley Hydrologic Advisory Committee, formed in 1987, instituted a monitoring program to collect data...

A study was conducted to determine the value of triticale (a hybrid between rye and wheat) as a substitute for wheat middlings in the diet of Atlantic salmon (Salmo salar). Data on growth and carcass composition of fish fed the experimental diets containing triticale were comparable to those of fish...

Well-constrained hypocenters (latitude, longitude, depth, and origin time) are required for nearly all studies that use earthquake data. We have examined the theoretical basis behind some of the widely accepted “rules of thumb” for obtaining accurate hypocenter estimates that pertain to the use of S phases and illustrate, in a...

Lava flows of the Ninole Basalt, the oldest rocks exposed on the south side of the island of Hawaii, provide age and compositional constraints on the evolution of Mauna Loa volcano and the southeastward age progression of Hawaiian volcanism. Although the tholeiitic Ninole Basalt differs from historic lavas of Mauna...

Simulation of transport affected by heterogeneous or homogeneous reversible reactions requires a choice between local equilibrium-based and kinetics-based models. The error associated with the use of equilibrium-based models is equivalent to the error of neglecting certain mathematical terms in the governing kinetics-based transport equations. Identification and evaluation of these kinetically...

A reconnaissance soil-gas helium survey was made in the Ely, Nevada and Delta, Utah 1° × 2° quadrangles in the Basin and Range Province. Helium concentrations in 510 samples ranged from −147 to 441 ppb He with respect to ambient air. The median helium value for the study area was...

By virtue of the images used in the dislocation solution, the deformation at the free surface produced throughout the earthquake cycle by slippage on a long strike-slip fault in an Earth model consisting of an elastic plate (lithosphere) overlying a viscoelastic half-space (asthenosphere) can be duplicated by prescribed slip on...

The Austrian reconnaissance study of stream-sediment composition — more than 30000 clay-fraction samples collected over an area of 40000 km2 — is summarized in an atlas of regional maps that show the distributions of 35 elements. These maps, rich in information, reveal complicated patterns of element abundance that are difficult...

On May 25, 1980, the resort town of Mammoth Lakes, California, was shaken by a remarkable 48-hour-long earthquake sequence that included four M=6, two M=5 and 300 M=3 quakes. The nature of the precursory seismicity plus the unusual character of the May 25-27 sequence itself suggested that it was not...

Colloidal materials, dispersed phases with dimensions between 0.001 and 1 μm, are potential transport media for a variety of contaminants in surface and ground water. Characterization of these colloids, and identification of the parameters that control their movement, are necessary before transport simulations can be attempted. Two techniques that can...

The Mule Mountains thrust system crops out discontinuously over a 100-km-strike length in the Blythe-Quartzsite region of southeast California and southwest Arizona. Along the thrust system, middle and upper crustal metamorphic and plutonic rocks of Proterozoic and Mesozoic age are thrust north-northeastward (015° to 035°) over a lower plate metamorphic...

A preliminary geologic map at 1:50,000 of the Lassen region encompasses 1400 km2. The map displays many small, monogenetic volcanoes of basalt to andesite as well as three major late Pliocene and Quaternary volcanic centers that have erupted products ranging from basaltic andesite to rhyolite. The youngest of these volcanic...

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...

As part of the paleohydrology study of the Yucca Mountain Project, strontium-isotope analyses of carbonate deposits, ground water, and major rock reservoirs of strontium are in progress. This paper presents a summary of the strontium-isotope data obtained through 1989. Calcium carbonate is ubiquitous in the vicinity of Yucca Mountain, where...

Organic geochemical investigations were conducted on a series of cores that systematically sampled the uppermost Jurassic strata from the northern Newark Basin. Each sedimentary unit consists of fluvial red sandstones and siltstones with cyclic deposits of interbedded black lacustrine shales and...

Experimental Thermal Infrared Multispectral Scanner (TIMS) aircraft data have been acquired for the Rodeo Creek NE 7 1/2 minute quadrangle, Eureka County, northern Nevada, covering the Carlin gold mine. A simple model has been developed to extract spectral emissivities for mapping surface lithology and alteration based on the physical properties...

The Wrangell volcanic field covers more than 10 000 km2 in southern Alaska and extends uninterrupted into northwest. Yukon Territory. Lavas in the field exhibit medium-K, calc-alkaline affinities, typical of continental volcanic arcs along convergent plate margins. Eleven major eruptive centers are recognized in the Alaskan part of the field....

Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on...

Long-term near-bottom wave and current observations and a one-dimensional sediment transport model are used to calculate the concentration and transport of sediment during winter storms at 60-80 m water depth along the southern flank of Georges Bank and in the Mid-Atlantic Bight. Calculations are presented for five stations, separated by...

Historically, sediment information has been used primarily in planning for engineering structures that were designed to meet a single or a very limited number of objectives. Today most water-resource systems are fully developed, but society is asking that the existing systems be operated to meet multiple objectives, which often were...