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A simple and powerful method for simulating ground motions is to combine parametric or functional descriptions of the ground motion's amplitude spectrum with a random phase spectrum modified such that the motion is distributed over a duration related to the earthquake magnitude and to the distance from the source. This...

The morphology and composition of spinel in rapidly quenched Pu'u 'O'o vent and lava tube samples are described. These samples contain glass, olivine phenocrysts (3-5 vol.%) and microphenocrysts of spinel (~0.05 vol.%). The spinel surrounded by glass occurs as idiomorphic octahedra 5-50 μm in diameter and as chains of octahedra...

Ground-motion records from a 52-element dense seismic array near San Jose, California, are analyzed to obtain site response, shallow shear-wave velocity, and plane-wave propagation characteristics. The array, located on the eastern side of the Santa Clara Valley south of the San Francisco Bay, is sited over the Evergreen basin, a...

The Greater Yellowstone Ecosystem contains the rare combination of an intact guild of native large carnivores, their prey, and differing land management policies (National Park versus National Forest; no hunting versus hunting). Concurrent field studies on large carnivores allowed us to investigate activities of humans and carnivores on Yellowstone National...

New sediment core data from a unique slow-sedimentation rate site in Lake Tanganyika contain a much longer and continuous record of limnological response to climate change than have been previously observed in equatorial regions of central Africa. The new core site was first located through an extensive seismic reflection survey...

[No abstract available]...

Damage caused by introduced species results from the high population densities and large body sizes that they attain in their new location. Escape from the effects of natural enemies is a frequent explanation given for the success of introduced species. Because some parasites can reduce host density and decrease body size,...

The relationship between nutritional status and disease resistance in cultured salmonids can be affected by dietary manipulations. Careful attention to feeding levels may be important to avoid imbalances in nutrient levels that could ultimately impair a fish's ability to resist infectious microorganisms. In the current study, fish in three feed-level...

The early Mesozoic Birdsboro basin (new name) was a single, elongate depositional trough in the present Mid-Atlantic area of the eastern United States, extending north-eastward from central Virginia across Maryland, Pennsylvania, and New Jersey into southern New York. What now remains after erosion comprises the Barboursville, Culpeper, Gettysburg, and Newark...

A rhyolitic hyaloclastite from Ponza Island, Italy, was hydrothermally altered, producing four distinct alteration zones based on X-ray diffraction mineralogy and field textures: (1) nonpervasive argillic zone; (2) propylitic zone; (3) silicic zone; and (4) sericitic zone. The unaltered hyaloclastite is volcanic breccia with clasts of vesiculated obsidian in a...

Goldquarryite, idealized formula CuCd2Al3(PO44F2(H2O)10(H2O 2, structure-derived formula (Cu0.70???0.30??1.00(Cd1.68Ca0.32??2.00Al3 (PO44F2(H2O)10[(H2O 1.60F0.40]??2.00, is triclinic, space group P1, with unit-cell parameters derived from crystal structure: a = 6.787(1), b = 9.082(2), c = 10.113(2) A??, ?? = 101.40(1)??, ?? = 104.27(1)??, ?? = 102.51(1)??, V = 568.7(3) A??3, a:b:c: = 0.7473:1:1.1135, Z =...

Voluminous Paleozoic sandstone sequences were deposited in northern Africa and Arabia following an extended Neoproterozoic orogenic cycle that culminated in the assembly of Gondwana. We measured sensitive high-resolution ion microprobe (SHRIMP) U-Pb ages of detrital zircons separated from several Cambrian units in the Elat area of southern Israel in order...

A high-resolution chronology for Peoria (last glacial period) Loess from three sites in Nebraska, midcontinental North America, is determined by applying optically stimulated luminescence (OSL) dating to 35-50 ??m quartz. At Bignell Hill, Nebraska, an OSL age of 25,000 yr near the contact of Peoria Loess with the underlying Gilman...

The Hudson Shelf Valley is a bathymetric low that extends across the continental shelf offshore of New York and New Jersey. From December 1999 to April 2000 a field experiment was carried out to investigate the transport of sediment in the shelf and valley system. Near-bed tripods and water-column moorings...

The development of The National Map is "national" in the broadest sense of the word. Although the U.S. Geological Survey is taking the lead, local governments, states, and regions are active and essential partners in the process, contributing, for example, data updates, problem-solving data integration, and map development from multiple...

Mechanisms for concentrating carbon around the Rubisco enzyme, which drives the carbon-reducing steps in photosynthesis, are widespread in plants; in vascular plants they are known as crassulacean acid metabolism (CAM) and C4 photosynthesis. CAM is common in desert succulents, tropical epiphytes, and aquatic plants and is characterized by nighttime fixation...

A sedimentary sequence penetrated in the lower part of the Grober-Fuqua #1 well in the southeastern Albuquerque Basin has previously been interpreted as either Triassic or Eocene in age. Paleomagnetic study of three specimens from two core fragments yielded a 54.5?? mean inclination of remanent magnetization relative to bedding. This...

Changes in the carbon isotope ratio (δ13C) of trans-1,2-dichloroethylene (t-DCE) were measured during its co-metabolic degradation by Methylomonas methanica, a type I methanotroph, and Methylosinus trichosporium OB3b, a type II methanotroph. In closed-vessel incubation experiments with each bacterium, the residual t-DCE became progressively enriched in 13C, indicating isotopic fractionation. From...

Three generations of mallard ducks (Anas platyrhynchos) were fed either a control diet or a diet containing 0.5 ppm mercury in the form of methylmercury. The levels of mercury in adult tissues and eggs remained about the same over 3 generations. The methylmercury diet had no effect on...

This study describes circadian and social movement patterns of 9 wolves and illustrates capabilities and limitations of Global Positioning System (GPS) telemetry for analysis of animal activity patterns. Wolves were studied at the Camp Ripley National Guard Training Site in Little Falls, Minnesota, and were captured via helicopter net-gunning. All...

Coalbed methane is produced from naturally fractured strata in the lower Pennsylvanian Pottsville Formation in the eastern part of the Black Warrior basin, Alabama. Major fracture systems include orthogonal fractures, which consist of systematic joints in siliciclastic strata and face...

Calculations indicate that the impact of an asteroid or comet on the Atlantic Coastal Plain 35 million years ago created subsequent hydrothermal activity and conditions suitable for phase separation and the creation of the brine observed in the groundwater at the site today. A calculation of groundwater velocity using Darcy's...

Benthic invertebrates play an important role in estuarine food webs and biogeochemical cycling of carbon, nutrients, and contaminants. The generally sedentary benthic invertebrates continuously integrate local water, sediment, and food conditions. This makes them good indicators of the type and quality of aquatic habitat at the location where they are...

This article presents time-series plots of specific-conductance, water-temperature, and water-level data collected in San Francisco Bay during water years 2001 and 2002 (October 1, 2000, through September 30, 2002). Specific-conductance and water-temperature data were recorded at 15-minute intervals at the following US Geological Survey (USGS) locations (Figure 1): • Suisun...

In northwestern Colorado, flow regulation on the Green River has created a transitional plant community that features encroachment by upland vegetation into cottonwood (Populus fremontii)-dominated, riparian forest on topographically high floodplain sites and reduced cottonwood regeneration on low floodplain sites. To assess how these changes might have affected small mammal...