Publications

When glacial cycles occur above low-permeability geologic formations, such as the shale and limestone units being considered for nuclear waste disposal in Canada, pressures may differ greatly from normal hydrostatic conditions. Although shale also often has the propensity to generate separate phase fluids like natural gas, it is largely uncertain how the processes that control this...

Winter is an understudied but key period for the socio-ecological systems of northeastern North American forests. A growing awareness of the importance of the winter season to forest ecosystems and surrounding communities has inspired several decades of research, both across the northern forest and at other mid- and high-latitude ecosystems around the globe. Despite these efforts, we...

Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes...

Estimation of low flows in rivers continues to be a vexing problem despite advances in statistical and process‐based hydrological models. We develop a method to estimate minimum streamflow at seasonal to annual timescales from measured streamflow based on regional similarity in the deviations of daily streamflow from minimum streamflow for a period of interest. The method is applied to 1...

The U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection, measured sediment oxygen demand (SOD) and benthic nutrient fluxes throughout Barnegat Bay, New Jersey. SOD was determined in situ using chambers equipped with optical dissolved oxygen sensors. The benthic nutrient fluxes of ammonia (NH3), nitrite + nitrate (plus ions; here, referred to...

Environmental conditions and management practices affect nutrient losses in surface runoff, but their relative impacts on phosphorus (P) loss during frozen and nonfrozen ground periods have not been well quantified. More specifically, the relative importance of manure application, tillage, and soil-test P (STP) has not been assessed at the field scale. In this study, we compiled a...

Water, bed sediment, and biota were sampled in selected streams from Butte to near Missoula, Montana, as part of a monitoring program in the Clark Fork Basin of western Montana. The sampling program was led by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to characterize aquatic resources in the Clark Fork Basin and emphasize trace elements...

Daily precipitation in California has been projected to become less frequent even as precipitation extremes intensify, leading to uncertainty in the overall response to climate warming. Precipitation extremes are historically associated with Atmospheric Rivers (ARs). Sixteen global climate models are evaluated for realism in modeled historical AR behavior and contribution of the...

In a recent U.S. Geological Survey/U.S. Environmental Protection Agency study assessing >700 organic compounds in 38 streams, in vitro assays indicated generally low estrogen, androgen, and glucocorticoid receptor activities, but identified 13 surface waters with 17β estradiol equivalent (E2Eq) activities greater than the 1 ng/L level of concern for feminization of male fish. Among the...

In 2015, the U.S. Geological Survey began a 1-year hydrologic study to investigate the extent and cause of inundation at Farm Creek Marsh, in Dorchester County, Maryland. In combination with a tide and precipitation gage, a representative section of the marsh was instrumented with surface-water monitors and shallow groundwater piezometers to capture the spatial and temporal extent of...

Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest’s influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in...

Atmospheric nitrate (NO3− = particulate NO3− + gas‐phase nitric acid [HNO3]) and sulfate (SO42−) are key molecules that play important roles in numerous atmospheric processes. Here, the seasonal cycles of NO3− and total suspended particulate sulfate (SO42−(TSP)) were evaluated at the South Pole from aerosol samples collected weekly for approximately 10 months (26 January to 25 October)...