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In June 2018, U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. A total of 35 horizontal-to-vertical spectral ratio (HVSR) passive seismic measurements were collected at the site. The HVSR technique uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of approximately 0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources. A resonance frequency (f0) is induced in the unconsolidated sediments when there...
From October 2016 to July 2018, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers and Maine Department of Transportation, collected surface, marine and borehole geophysical surveys to characterize the subsurface materials on land and under the water at a former mine facility in Brooksville, Maine. Borehole geophysical logs were collected from May 2-3, 2017 in five boreholes to identify geophysical properties, including the electrical properties and natural gamma emissions. In addition, fluid electrical conductivity and temperature were collected through the water column in the well. Results can be used to identify the water level and the lithologic contacts in the subsurface. Natural...
In May 2017 and July 2018, continuous resistivity profiling (CRP) surveys were collected in Goose Pond at the Callahan Mine site. CRP tool was used to characterize the resistivity of the water column and subbottom layers. For this investigation, 11 electrodes spaced 10 m apart and mounted in a streamer were towed behind the boat. The first two electrodes, closest to the boat, were used to inject current into the water and subbottom materials, and eight electrical potential measurements were made using the remaining nine electrodes in dipole-dipole configuration. With this system, a complete suite of measurements is collected every 2.8 seconds. Because the boat was moving at a slow rate of speed, a complete measurement...
In March 2016, the U.S. Geological Survey drilled a borehole, MA-FSW-750-0100, through the unconsolidated sediments and 1.5 m into the bedrock in East Falmouth, Massachusetts, to improve understanding of the glacial history and hydrologic properties of the Cape Cod aquifer. Prior to drilling, candidate sites were investigated using surface geophysical methods. Passive seismic horizontal-to-vertical spectral ratio (HVSR) methods were used to estimate the depth of the unconsolidated deposits over bedrock. Transient electromagnetic (TEM) surveys were conducted to characterize the lithology and salinity of formation water in the subsurface, which was used to plan the borehole completion. The specific conductance of...
A pulsed magnetic resonance borehole tool was used to characterize hydraulic properties of the aquifer. Borehole nuclear magnetic resonance (bNMR) logs were collected to measure the water content and to estimate the pore-size distribution and hydraulic conductivity (K) over the depth of the borehole. The bNMR data were collected July 25-26, 2016, and were processed August 2016.
In March 2016, the U.S. Geological Survey drilled a borehole, MA-FSW-750, through the unconsolidated sediments and 1.5 m into the bedrock in East Falmouth, Massachusetts, to improve understanding of the glacial history and hydrologic properties of the Cape Cod aquifer. Polyvinyl casing was set through the overburden and into the bedrock. About 10 days after borehole MA-FSW-750 was drilled, it was logged with geophysical methods including natural gamma radiation and electromagnetic induction (EMI) logs to identify changes in the lithology and fluid properties of the subsurface. In addition, the gamma and EMI logs were collected about 100 days after drilling, which allowed the drilling fluids to be displaced and natural...
Passive seismic horizontal-to-vertical spectral ratio (HVSR) methods were used to estimate the depth of the unconsolidated deposits over bedrock. The HVSR method uses a three-component seismometer to measure the vertical and two horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources. A resonance frequency (f0) is induced in the unconsolidated deposits when there is a substantial contrast (> 2:1) in shear-wave acoustic impedance between the overburden and the bedrock. The f0 is determined from the analysis of the spectral ratio of the horizontal and vertical components of the seismic data. The thickness...
The salinity of groundwater at the Florida Power & Light Company (FPL) Turkey Point Nuclear Plant in southeastern Florida is being evaluated. The power plant contains a large cooling canal system with warm water; which has salinities elevated above typical, natural surface water in southeastern Florida, circulating within the canals in the uppermost part the highly permeable karst carbonate Biscayne aquifer. The canal system is a closed system that does not discharge directly to fresh or marine surface water bodies. However, exchange between the canal system and groundwater has been postulated based on existing hydrologic information. A pilot study was conducted to determine if Continuous resistivity profiles could...
Types: Citation;
Tags: Biscayne Bay,
CRP,
Continous Resistivity Profiling,
Cooling Canal System,
Florida,
A continuous resistivity profiling (CRP) survey was conducted in a 1.2-mile reach of the Similkameen River upstream of Enloe Dam in December 2021 in Washington State. The survey was performed to characterize the resistivity of the water column and subbottom materials using the CRP method. The survey consisted of eight longitudinal profiles roughly equivalent in length and conducted in the right, left and center of the channel. In this survey, a 100-m cable with 11 electrodes spaced 10 m apart and outfitted with floatation aids was towed behind a boat at speeds of 1-1.5 m/s and data were collected using the dipole-dipole array type. In this configuration, two electrodes nearest the boat transmitted electric current...
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