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The Chandeleur Islands are a chain of barrier islands that lies along the eastern side of the modern Mississippi River Delta plain. The island chain is located near the seaward edge of the relict St. Bernard Delta, the part of the Mississippi Delta that formed between approximately 4,000 and 2,000...

A study of dewatering of the fractured-bedrock aquifer in a localized area of east-central North Carolina was conducted from March 2008 through February 2009 to gain an understanding of why some privately owned wells and monitoring wells were intermittently dry. Although the study itself was localized in nature, the resulting...

In 2007, the US Geological Survey initiated a low-density (1 site per 1600 km2, c. 4800 sites) geochemical and mineralogical survey of soils of the conterminous USA. The ideal sampling protocol at each site includes a sample from 0–5 cm depth, a composite of the soil A horizon, and a sample from...

On May 25-27, 1980, Long Valley caldera was rocked by four M=6 earthquakes that heralded the onset of a wave of seismic activity within the caldera which has continued through the present. Unrest has taken the form of seismic swarms, uplift of the resurgent dome, and areas of vegetation killed...

High seismicity levels with accelerating uplift (under the resurgent dome) in Long Valley caldera in the eastern Sierra Nevada from 1989 to 1997, triggered upgrades to dilational strainmeters and other instrumentation installed in the early 1980's following a series of magnitude 6 earthquakes. This included two additional high-resolution borehole strainmeters...

Rapid changes in ground tilt and GPS positions on Kīlauea Volcano, Hawai'i, are interpreted as resulting from a shallow, two‐segment dike intrusion into the east rift zone that began at 1217 UTC (0217 HST) on 17 June 2007 and lasted almost 3 days. As a result...

No abstract available....

The purpose of the U.S. Geological Survey (USGS) National Oil and Gas Assessment is to develop geology-based hypotheses regarding the potential for additions to oil and gas reserves in priority areas of the United States, focusing on the distribution, quantity, and availability of oil and natural gas resources. The USGS...

Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover...

The St. Petersburg Coastal and Marine Science Center of the U.S. Geological Survey (USGS) investigates physical processes related to coastal and marine environments and societal implications related to natural hazards, resource sustainability, and environmental change. Immediately after the Deepwater Horizon event, the USGS began responding to data requests, directing response...

Parts of the northern Great Plains in eastern Montana and western North Dakota and southeastern Alberta and southwestern Saskatchewan, Canada, were studied as part of an assessment of shallow biogenic gas in Upper Cretaceous rocks.Parts of the northern Great Plains in eastern Montana and western North Dakota and southeastern Alberta...

This report, prepared in cooperation with the Pennsylvania Department of Environmental Protection (PaDEP), the Eastern Pennsylvania Coalition for Abandoned Mine Reclamation, and the Dauphin County Conservation District, provides estimates of water budgets and groundwater volumes stored in abandoned underground mines in the Western Middle Anthracite Coalfield, which encompasses an area...

Quartz diorite bedrock underlying the Luquillo Mountains of eastern Puerto Rico undergoes weathering at one of the fastest documented rates for granitic rocks in the world. Although tropical temperatures and precipitation promote rapid weathering in this location, increased bacterial densities in the regolith immediately above the bedrock suggest that microorganisms...

The movement and transmission of avian influenza viral strains via wild migratory birds may vary by host species as a result of migratory tendency and sympatry with other infected individuals. To examine the roles of host migratory tendency and species sympatry on the movement of Eurasian low-pathogenic avian influenza (LPAI)...

Groundwater in the Newark basin aquifer flows primarily through discrete water-bearing zones parallel to the strike and dip of bedding, whereas flow perpendicular to the strike is restricted, thereby imparting anisotropy to the groundwater flow field. The finite-element model SUTRA was used to represent bedrock structure in the aquifer by...

In 2010, a two-dimensional hydrodynamic and water-quality model (CE-QUAL-W2) of Lake Ashtabula, North Dakota, was developed by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission to understand the dynamics of chemical constituents in the reservoir and to provide a tool for the management and operation...

The Greater Platte River Basin area spans a central part of the Midcontinent and Great Plains from the Rocky Mountains on the west to the Missouri River on the east, and is defined to include drainage areas of the Platte, Niobrara, and Republican Rivers, the Rainwater Basin, and other adjoining...

The superlative hot springs, geysers, and fumarole fields of Yellowstone National Park are vivid reminders of a recent volcanic past. Volcanism on an immense scale largely shaped the unique landscape of central and western Yellowstone Park, and intimately related tectonism and seismicity continue even now. Furthermore, the volcanism that gave...

What are the roles of deep Precambrian basement deformation zones in the localization of subsequent shallow-crustal deformation zones and magmas? The Paleoproterozoic Great Falls tectonic zone and its included Boulder batholith (Montana, United States) provide an opportunity to examine the importance of inherited deformation fabrics in batholith emplacement and the...

The San Jacinto right-lateral strike-slip fault zone is crucial for understanding plate-boundary dynamics, regional slip partitioning, and seismic hazards within the San Andreas fault system of southern California, yet its age of initiation and long-term average slip rate are controversial. This synthesis of prior and new detailed studies in the...

This report documents selected age data interpreted from measured concentrations of environmental tracers in groundwater from 1,399 National Water-Quality Assessment (NAWQA) Program groundwater sites across the United States. The tracers of interest were chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), and tritium/helium-3 (3H/3He).Tracer data compiled for this analysis primarily were from wells...

The hydrogeology of the stratified-drift aquifer in the Sprout Creek and Fishkill Creek valleys in southern Dutchess County, New York, previously investigated by the U.S. Geological Survey (USGS) in 1982, was updated through the use of new well data made available through the New York State Department of Environmental Conservation's...

Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at...

Rusa unicolor (Kerr, 1792), or sambar, is the largest Oriental deer. Seven subspecies occur in varied habitats and elevations from India and Sri Lanka throughout southeastern Asia. Body mass and antler length decrease from west to east. R. unicolor is considered ancestral relative to the form of its male-only antlers...

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces...