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Thermodynamic evaluation and restoration procedures are applied to a set of 10 volcanic gas analyses obtained by modern collection and analytical methods. The samples were collected from a vigorously fuming fissure during episode 1 of the Puu Oo eruption of Kilauea Volcano in 1983. A variety of analytical techniques were...

IT is widely understood that the collapse of the West Antarctic ice sheet (WAIS) would cause a global sea level rise of 6 m, yet there continues to be considerable debate about the detailed response of this ice sheet to climate change1-3. Because its bed is grounded well below sea...

The possible impact of periglacial climates on the rate of chemical weathering of a coarse-grained plagioclase-muscovite-quartz schist has been determined for a small watershed near Baltimore, Maryland. The isovolumetric chemical weathering model formulated from the geochemical mass balance study of the watershed...

Paleowaters from the Floridan aquifer system in the southeastern Atlantic coastal plain have higher D/H and 18O/16O ratios than local Holocene ground water. Maximum...

Mono Lake is a terminal, saline lake that became ectogenically meromictic in 1982–1983 and remained stratified until November 1988. During this period, the monimolimnion remained anoxic and nearly isothermal, while the upper mixolimnion was well oxygenated and exhibited a seasonal thermal regime. Dissolved sulfide and methane increased...

The abundance and distribution of dissolved CH4 were determined from 1987-1990 in Lake Fryxell, Antarctica, an amictic, permanently ice-covered lake in which solute movement is controlled by diffusion. CH4 concentrations were < 1 ??M in the upper oxic waters, but increased below the oxycline to 936 ??M at 18 m....

The sorption of hydrophobic organic chemicals (HOCs) to ??-Al2O3 was investigated with a headspace analysis method. The semiautomated headspace analyzer gave rapid, precise, and accurate results for a homologous series alkylbenzenes even at low percentages of solute mass sorbed (3-50%). Sorption experiments carried out with benzene alone indicated weak interactions...

Commonly used techniques for the concentration and isolation of organic matter from water, such as preparative chromatography, ultrafiltration and reverse osmosis, and the methods used to analyze the organic matter obtained by these methods are reviewed. The development of methods to obtain organic matter that is associated with fractions of...

Sediments from three gravity cores from an east-west shelf-to-slope transect along the axis of Pervenets Canyon in the northern Navarin basin, Bering Sea were analyzed for diatoms. The diatom floras present in the cores were divided into four assemblages following Sancetta (1981). The Bering Basin (deep water open ocean) and...

A study was conducted during 1990 through an 11.2-km reach of Roberts Creek in northeastern Iowa to determine the fate of atrazine in a surface water environment Water samples were collected at ~1-month intervals from April through November during stable low to medium flow conditions and analyzed for atrazine and...

A harmonic decomposition technique is applied to the shallow water equations to yield a complex, nonsymmetric, nonlinear, Helmholtz type problem for the sea surface and an accompanying complex, nonlinear diagonal problem for the velocities. The equation for the sea surface is linearized using successive approximation and then discretized with linear,...

A field study was conducted to evaluate the environmental dissipation of triclopyr herbicide under aquatic-use conditions. Three 4-h plots in Lake Seminole, Georgia, were selected for use: one control, one aerial plot, and one subsurface plot; both applications were at the maximum aquatic-use rate of 2.5 mg/L. Water, sediment, plants,...

Gas hydrates are crystalline substances composed of water and gas, mainly methane, in which a solid-water lattice accommodates gas molecules in a cage-like structure, or clathrate. These substances commonly have been regarded as a potential unconventional source of natural gas because of their enormous gas-storage capacity. Significant quantities of naturally...

Within the last decade, a novel form of microbial metabolism of major environmental significance has been elucidated. In this process, known as dissimilatory metal reduction, specialized microorganisms, living in anoxic aquatic sediments and ground water, oxidize organic compounds to carbon dioxide with metals serving as the oxidant. Recent studies have...

The Baid al Jimalah tungsten deposit in Saudi Arabia (lat 25 degrees 09'N, long 42 degrees 41'E) consists predominantly of swarms of steeply dipping, subparallel, tungsten-bearing quartz veins and of less abundant, smaller stockwork veins. It is spatially, temporally, and genetically associated with a 569 Ma, highly differentiated, porphyritic, two-feldspar...

Quaternary basanites were recovered from shallow water depth from the continental margin of the Bering Sea (58°39.0′N, 177°12.9′W) near Navarin Basin. The basanites are highly vesicular flow rock and hyaloclastites similar to other alkalic volcanic rocks erupted repeatedly during the late Cenozoic on islands in the Bering Sea region and...

By analyzing two landslides in the New Madrid seismic zone, we develop an approach for judging if a landslide or group of landslides of unknown origin was more likely to have formed as a result of earthquake shaking or in aseismic conditions. The two landslides analyzed are representative of two...

At Yucca Mountain, calcite occurs as open-space fillings and coatings on fractures within much of the host volcanic rocks in both the saturated and unsaturated zones. Strontium isotope analyses of these calcites divide the samples into two groups corresponding to their location in either the saturated or unsaturated zones. The...

Since 1982, imported water originating in the Sierra Nevada has been used to recharge the Rialto-Colton ground-water basin, about 100 km east of Los Angeles. Stable isotopes of oxygen (oxygen-18) and hydrogen (deuterium) were used to determine the disposition of artificially recharged, imported water within the basin. Delta oxygen-18 ratios...

The 234U/238U ratio of uranium in oxidizing ground waters is potentially an excellent ground-water tracer because of its high solubility and insensitivity to chemical reactions. Moreover, recent advances in analytical capability have made possible very precise uranium-isotopic analyses on modest (approx.100 ml) amounts of normal ground water. Preliminary results on...

The gases dissolved in Lake Nyos, Cameroon, were quantified recently (December 1989 and September 1990) by two independent techniques: in-situ measurements using a newly designed probe and laboratory analyses of samples collected in pre-evacuated stainless steel cylinders. The highest concentrations of CO2 and CH4 were...

Two methods are currently available for determining contaminant assimilation efficiencies (AE) from ingested material in benthic invertebrates. These methods were compared using the Great Lakes amphipod Diporeia spp. and [14C]benzo(a)pyrene (BaP) sorbed to Florissant sediment (< 63 µm). The first approach, the direct measurement method, uses total organic carbon as...

Tourmaline-rich rocks are widespread minor lithologies within the Early Proterozoic Willyama Supergroup in the Broken Hill district, Australia. Tourmaline concentrations occur in strata-bound and local stratiform tourmalinites, clastic metasedimentary rocks, quartz-gahnite lode rocks, stratiform Pb-Zn-Ag sulfide ores, garnet quartzites, strata-bound scheelite deposits, quartz-tourmaline nodules, discordant quartz veins, and granitic pegmatites....

Three modern sedimentary environments have been identified and mapped across the glaciated Boston Harbor estuary and adjacent inner shelf of Massachusetts Bay by means of an extensive set of sidescan sonar records and supplemental bathymetric, sedimentary, subbottom and bottom-current data. 1. (1) Environments of erosion and nondeposition appear on the...

Five general core sealing methods (using Protecore, Lexan, wax, Protecore with wax, and Protecore with Lexan) were studied over a two year period to determine their moisture retention capabilities. Results indicate that the multibarrier methods (Protecore with wax and Protecore with Lexan) and the single barrier methods (Protecore and wax)...