Public Release: 

New device offers more detailed look at aquifers

University of Wyoming

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IMAGE: An operator from Vista Clara, the company that manufactures borehole nuclear magnetic resonance instruments, left, and a technician from the Kansas Geological Society, demonstrate the use of the Javelin. view more

Credit: Andrew Parsekian

The University of Wyoming will soon receive a new piece of equipment that will more accurately measure aquifer levels in the ground.

UW's Wyoming Center for Environmental Hydrology and Geophysics (WyCEHG) received a two-year, $408,000 National Science Foundation (NSF) Major Instrument Research Award for a borehole nuclear magnetic resonance (NMR) instrument. This geophysical tool, also referred to as a Javelin, can be deployed into boreholes and analyze how much water is in the aquifer and how easy or difficult it might be to extract that water. The instrument works on the same physical principles as medical MRI imaging.

"This is a relatively new technology for water," says Andrew Parsekian, an assistant professor in UW's Department of Geology and Geophysics as well as the Department of Architectural and Civil Engineering. "The technology has been used for decades in the oil exploration industry. However, it has only emerged for use in hydrogeology within the past few years. This borehole NMR instrument will be the only one owned and operated by an academic institution in the United States at the current time."

Bill Gern, UW's vice president for research and economic development, says the piece of equipment "fills out the WyCEHG instrumentation suite for examination of subsurface hydrology. This will help UW become one of the top five universities in subsurface hydrology in the United States."

Parsekian says the instrument will be used to visualize where water is stored underground; what the geometric properties of aquifers are; and how water changes over time. Initially, the instrument is scheduled to make measurements on projects related to fractured-rock aquifers; permafrost thaw, which releases carbons into the atmosphere; weathering in the Critical Zone (everything between the ground surface and the bottom of the aquifer, including plants, soil and rocks); and return flow from irrigation and macro-pore flow into tropical soils.

The instrument, which can log boreholes as small as 2 inches in diameter, will first be used for a water return flow study in Dubois, where a contained catchment is located, Parsekian says. The Javelin also will be used in the Laramie Range during the winter to measure WyCEHG wells located there, he adds.

"Making these measurements with traditional tools can be really difficult and hard to get high spatial resolution," Parsekian explains. "Using this geological tool that can measure where the water is and how fast it moves is exciting."

By emitting a series of radio-frequency pulses and recording the returning signal, the Javelin measures the NMR response of groundwater in the sensitive zone, much like an MRI scanner measures the NMR response of tissues in the body, according to the Vista Clara Inc. website. Vista Clara, a company based in Mukilteo, Wash., manufactures the instrument.

"A hydrologist wants to know how much water is in the aquifer; how easily can you extract it; or how fast does it move away from your area," Parsekian says.

While the NSF award was officially granted July 15, the borehole NMR instrument will take at least six months to build, Parsekian says.

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