Only ten years after the increased addition of methyl-tert-butylether (MTBE) to U.S. gasolines, nationwide MTBE contamination of thousands of drinking water supply wells has been widely documented, reflecting enormous environmental and economic costs. Due to its abundance in gasoline, high aqueous solubility, and slow degradation rate in aquifers, MTBE has migrated in significant quantities fro...

The ARS Root Zone Water Quality Model (RZWQM ver. 3.25) was used to simulate the effect of field measured macroporosity on atrazine transport to subsurface drain lines. Field data on atrazine concentrations in subsurface drain flow from corn fields, for modified no-till (mNT) and moldboard plow (MP) systems, were used to evaluate the performance of the RZWQM for the growing seasons of 1990, 199...

An important seismic attenuation mechanism in fractured environments is related to energy conversion into reflected and transmitted waves at fracture interfaces. Using full-waveform sonic (FWS) log data, we show that it possible quantify transmission losses across a set of fractures from time delays amplitude differences the critically refracted P-wave as compared intact sections along borehole...

[1] The role of upslope soil pore water pressure on lateral subsurface storm flow dynamics is poorly understood. Further development of hillslope hydrologic models requires new understanding from field understanding. In particular, we need new, quantifiable measures that link upslope soil pore pressure and water table dynamics to the timing and volume of subsurface storm flow. Here we examine t...

Thirty-two chemoheterotrophic bacteria were isolated from unsaturated subsurface soil samples obtained from ca. 70 m below land surface in a high desert in southeastern Idaho. Most isolates were gram positive (84%) and strict aerobes (79%). Acridine orange direct counts of microbes in one subsurface sample showed lower numbers than similar counts performed on surface soils from the same locatio...

[1] A model to simulate the complete planetary orbital radar sounder problem is presented in this paper. The subsurface features and the ionosphere will not only bring ambiguity to the collected radar sounder data, but also critically affect instrument capabilities. These environmental uncertainties generate a compelling need for meaningful quantitative simulation of the orbital radar sounder p...

Against the background of increasing nutrient concentrations in Irish water bodies, this study set out to gain information on the potential of agricultural grassland to lose nutrients to water. Overland flow, flow from artificial subsurface drains and stream flow were gauged and sampled during heavy rainfall events. Dissolved reactive phosphorus (DRP), potassium (K), total ammonia (TA), and tot...

Seismic interferometry processing is applied to an active seismic survey collected on ocean bottom seismometers (OBS) deployed at 900-m water depth over a carbonate/ hydrates mound in the Gulf of Mexico. Common midpoint processing and stacking of the extracted Green’s function gives the subsurface PP reflectivity, with a horizontal resolution of half the receiver spacing. The obtained seismic s...

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Systemic sclerosis (SSc) is an autoimmune disorder that causes fibrosis in the skin and internal organs, including heart. Patients with SSc can have right ventricular (RV) systolic dysfunction absence pulmonary hypertension. Studies shown a predilection for impairment mid apical segments RV free wall compared to contr...