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A prominent unconformity, present across shallow shelf areas of the Euramerican paleoequatorial basins, is used to demark the boundary between the Mississippian and Pennsylvanian subsystems. This unconformity, the mid-Carboniferous eustatic event, is generally attributed to a major glacio-eustatic sea-level fall. Although a Mississippian-Pennsylvanian unconformity is recognized throughout most of the...

The Southern giant petrel (Macronectes giganteus) is declining over much of its range and currently is listed as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN). Island-specific breeding colonies near Palmer Station, Antarctica, have been monitored for over 30 years, and because this population continues to...

The 29 July 2008 Mw 5.4 Chino Hills earthquake was the largest event to occur within the greater Los Angeles metropolitan region since the Mw 6.7 1994 Northridge earthquake. The earthquake was widely felt in a metropolitan region with a population of more than 10 million people and was recorded...

In June 2006, an opportunistic high-flow release was made from Tiber Dam on the Marias River in Mont., to investigate possible alternatives for partially restoring the river's natural flow pattern and variability. At two sites along the river, we measured channel geometry before and after the high-flow release to evaluate...

Estimating sediment thickness and the geometry of the bedrock surface is a key component of many hydrogeologic studies. The horizontal‐to‐vertical (H/V) ambient‐noise seismic method is a novel, non‐invasive technique that can be used to rapidly estimate the depth to bedrock. The H/V method uses a single, broad‐band three‐component seismometer to...

Submarine ground‐water discharge (SGD) contributes important solute fluxes to coastal waters. Pollutants are transported to coastal ecosystems by SGD at spatially and temporally variable rates. New approaches are needed to characterize the effects of storm‐event, tidal, and seasonal forcing on SGD. Here, we evaluate the utility of two geophysical methods‐fiber‐optic...

DOI: 10.2111/1551-501X(2008)30[25:IRHRTM]2.0.CO;2...

The utility of the multi‐channel analysis of surface waves (MASW) seismic method for non‐invasive assessment of earthen levees was evaluated for a section of the Citrus Lakefront Levee, New Orleans, Louisiana. This test was conducted after the New Orleans' area levee system had been stressed by Hurricane Katrina in 2005....

The Yakima River Decision Support System (YRDSS) was designed to quantify and display the consequences of different water management scenarios for a variety of state variables in the upper Yakima River Basin, located in central Washington. The impetus for the YRDSS was the Yakima River Basin Water Storage Feasibility Study,...

Trammel netting is generally the accepted method of monitoring razorback sucker in reservoirs, but this method is ineffective for monitoring this fish in rivers. Trammel nets set in the current become fouled with debris, and nets set in backwaters capture high numbers of nontarget species. Nontargeted fish composed 97 percent...

Estimates of numbers of mineral deposits are fundamental to assessing undiscovered mineral resources. Just as frequencies of grades and tonnages of well-explored deposits can be used to represent the grades and tonnages of undiscovered deposits, the density of deposits (deposits/area) in well-explored control areas can serve to represent the number...

Analysis with a three‐dimensional variably saturated groundwater flow model provides a basic understanding of the interplay between streams and perched groundwater. A simplified, layered model of heterogeneity was used to explore these relationships. Base flow contribution from perched groundwater was evaluated with regard to varying hydrogeologic conditions, including the size...

Several abandoned Cu mines are located along the shore of Prince William Sound, AK, where the effect of mining-related discharge upon shoreline ecosystems is unknown. To determine the magnitude of this effect at the former Beatson mine, the largest Cu mine in the region and a Besshi-type massive sulfide ore...

It has become increasingly apparent that diet can be a major source of trace metal bioaccumulation in aquatic organisms. In this study, we examined cadmium uptake, efflux, and subcellular compartmentalization dynamics in the freshwater oligochaete Lumbriculus variegatus. L. variegatus is an important component of freshwater food webs in Europe and...

An annual daytime bottom trawl survey of the Lake Superior fish community designed in 1978 does not adequately assess the entire community. Whereas recent studies have recommended that pelagic species be surveyed with a combination of acoustic and midwater trawling methods (AC-MT), we used bottom trawling to study the effects...

Landslides in partially saturated colluvium on Seattle, WA, hillslopes have resulted in property damage and human casualties. We developed statistical models of colluvium and shallow-groundwater distributions to aid landslide hazard assessments. The models were developed using a geographic information system, digital geologic maps, digital topography, subsurface exploration results, the groundwater...

Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate...

In the present study, a spectral analysis was applied to field data and a numerical model of southeastern Everglades and northeastern Florida Bay that involved computing and comparing the power spectrum of simulated and measured flows at the primary coastal outflow creek. Four dominant power frequencies, corresponding to the S1,...

Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km2 in the western part of the...

Black spruce forests are a dominant covertype in the boreal forest region, and they inhabit landscapes that span a wide range of hydrologic and thermal conditions. These forests often have large stores of soil organic carbon. Recent increases in temperature at northern latitudes may be stimulating decomposition rates of...

The temporal and spatial structure of 332 404 daily fire-start records from the western United States for the period 1986 through 1996 is illustrated using several complimentary visualisation techniques. We supplement maps and time series plots with Hovmo??ller diagrams that reduce the spatial dimensionality of the daily data in order...

Twenty-eight Harlequin Ducks (Histrionicus histrionicus) and 26 Barrow's Goldeneyes (Bucephala islandica) were captured in Prince William Sound, Alaska, between 1 and 15 March 2005. Blood was collected for quantification of element concentrations, prevalence of antibodies to several viruses, and hemoparasite prevalence and identification. Although we found selenium concentrations that have...

The permeability of continental crust is so highly variable that it is often considered to defy systematic characterization. However, despite this variability, some order has been gleaned from globally compiled data. What accounts for the apparent coherence of mean permeability in the continental crust (and permeability–depth relations) on a very...

Dynamic stresses associated with crustal surface waves with 15-30-sec periods and peak amplitudes < 1 MPa are capable of triggering seismicity at sites remote from the generating mainshock under appropriate conditions. Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid-onset triggered seismicity that...

[1] A new groundwater dating procedure using the transient atmospheric signal of the environmental tracers SF5CF3, CFC-13, SF6, and CFC-12 was developed. The analytical procedure determines concentrations of the four tracers in air and water samples. SF 5CF3 and CFC-13 can be used to date groundwaters in some environments where...