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The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) is conducting a regional analysis of water quality in the principal aquifer systems across the United States. The Southwest Principal Aquifers (SWPA) study is building a better understanding of the susceptibility and vulnerability of basin-fill aquifers in the...

This product "Digital spatial data for predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area" is a 1:250,000-scale vector spatial dataset developed as part of a regional Southwest Principal Aquifers (SWPA) study (Anning and others, 2012). The study examined the vulnerability of basin-fill aquifers...

Digital flood-inundation maps for selected reaches of South Fork Licking River, Raccoon Creek, North Fork Licking River, and the Licking River in Licking County, Ohio, were created by the U.S. Geological Survey (USGS), in cooperation with the Ohio Department of Transportation; U.S. Department of Transportation, Federal Highway Administration; Muskingum Watershed...

This report documents data collected by the U.S. Geological Survey (USGS) for the Coastal Model Applications and Field Measurements project under the auspices of the U.S. Navy Office of Naval Research Optics, Acoustics, and Stress In Situ (OASIS) Project. The objective of the measurements was to relate optical and acoustic...

I am grateful to Masciopinto (2012) for raising several issues from my study (Nimmo, 2010) that deserve elaboration or clarification. In this reply, I address these in what I judge to be the order of importance, the main ones being (i) the discrepancy of scales between the two domains that...

Juvenile Chinook salmon (Oncorhynchus tshawytscha) emigrating from natal tributaries of the Sacramento River may use a number of migration routes to negotiate the Sacramento-San Joaquin River Delta (hereafter, "the Delta"), each of which may influence their probability of surviving. We applied a mark-recapture model to data from acoustically tagged juvenile...

The Sacramento River and its tributaries support populations of anadromous fish species including winter-run, spring-run, fall-run, and late fall–run Chinook salmon (Oncorhynchus tshawytscha); and steelhead (O. mykiss). Several of these species are listed as threatened or endangered under the California Endangered Species Act (CESA), federal Endangered Species Act (ESA), or...

The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the...

A numerical transient model of the surficial and Floridan aquifer systems in east-central Florida was developed to (1) increase the understanding of water exchanges between the surficial and the Floridan aquifer systems, (2) assess the recharge rates to the surficial aquifer system from infiltration through the unsaturated zone and (3)...

Digital flood-inundation maps for a 6.9-mile reach of Suwanee Creek, from the confluence of Ivy Creek to the Noblin Ridge Drive bridge, were developed by the U.S. Geological Survey (USGS) in cooperation with Gwinnett County, Georgia. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science...

Executive Summary Data from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) have been captured and tagged with passive integrated transponder (PIT) tags during...

The ASTER Global Digital Elevation Model Version 2 (GDEM v2) was evaluated over the conterminous United States in a manner similar to the validation conducted for the original GDEM Version 1 (v1) in 2009. The absolute vertical accuracy of GDEM v2 was calculated by comparison with more than 18,000 independent...

Love and Gannon (2009) discovered that statistically, over a fifty year period the difference in the dawn and dusk disturbance‐field H component at low latitudes (hourly averaged) is linearly proportional to Dst. If the difference is designated by δDD in units of nT/RE, then the Love‐Gannon (L‐G) relation is δDD = −0.2 Dst. At any time departures from the relation can...

Sandbars are an important aquatic terrestrial transition zone (ATTZ) in the active channel of rivers that provide a variety of habitat conditions for riverine biota. Channelization and flow regulation in many large rivers have diminished sandbar habitats and their rehabilitation is a priority. We developed sandbar-specific models of discharge-area relationships...

Analyzing telemetry data within a mark–recapture framework is a powerful approach for estimating demographic parameters (e.g., survival and movement probabilities) that might otherwise be difficult to measure. Yet many studies using telemetry techniques focus on fish behavior and fail to recognize the potential of telemetry data to provide information about...

Fish passage is the result of a sequence of processes, whereby fish must approach, enter, and pass a structure. Each of these processes takes time, and fishway performance is best quantified in terms of the rates at which each process is completed. Optimal performance is achieved by maximizing the rates...

Studies of the effects of hydroelectric dams on fish populations are common (Williams 2008). Dams block passage of migratory and resident fish, alter habitats from free-flowing to lacustrine, and can alter water temperatures both upstream and downstream. At some dams, structures or operations are modified to reduce their effects on...

Executive Summary Marine and estuarine nonindigenous species (NIS) are found across the world’s oceans, and designing effective management strategies to mitigate this economic, ecological and human health threat requires a basic understanding of the existing invasion patterns at regional to global scales. However, to date, syntheses at ocean basin scales have...

Biotelemetry has been defined as “the instrumental technique for gaining and transmitting information from a living organism and its environment to a remote observer” (Slater 1965). Biotelemetry typically utilizes wireless transmission of either an audible signal or electronic data to determine location of a tagged animal. Fisheries researchers use location...

Increased nutrient loading to estuaries has led to eutrophication, degraded water quality, and ecological transformations. Quantifying nutrient loads in systems with significant groundwater input can be difficult due to the challenge of measuring groundwater fluxes. We quantified tidal and freshwater fluxes over an 8-week period at the entrance of West...

Increases in ocean surface water dissolved carbon dioxide (CO2) concentrations retard biocalcification by reducing calcite supersaturation (Ωc). Reduced calcification rates may influence growth-rate dependent magnesium ion (Mg) incorporation into biogenic calcite modifying the use of calcifying organisms as paleoclimate proxies. Fulvic acid (FA) at biocalcification sites may further reduce calcification...

The martian polar regions have layered deposits of ice and dust. The stratigraphy of these deposits is exposed within scarps and trough walls and is thought to have formed due to climate variations in the past. Insolation has varied significantly over time and caused dramatic changes in climate, but it...

This brief report, drawing from a multi-year effort by the U.S. Agency for International Development (USAID) Famine Early Warning Systems Network (FEWS NET), identifies modest declines in rainfall, accompanied by increases in air temperatures. These analyses are based on quality-controlled station observations. Conclusions: * Summer rains have remained relatively steady...

Marine overwash from the north a few centuries ago transported hundreds of angular cobbles and boulders tens to hundreds of meters southward from limestone outcrops in the interior of Anegada, 140 km east–northeast of Puerto Rico. We examined two of several cobble and boulder fields as part of an effort...

Hungry Horse Dam on the South Fork Flathead River, Montana, USA, has modified the natural flow regimen for power generation, flood risk management and flow augmentation for anadromous fish recovery in the Columbia River. Concern over the detrimental effects of dam operations on native resident fishes prompted research to quantify...