Friday, October 17, 2014

Rock drilling leads WyCEHG scientists to groundwater

Not far from the Blair-Wallis picnic area in Vedauwoo near Laramie,Wyoming, literal breakthroughs in science are underway. A drill rig standing several stories tall and manned by four men wearing hard hats is moving, slowly. The drill is cutting through granite and pulling out long cylindrical core samples that offer UW’s Wyoming Center for Environmental Hydrology and Geophysics (WyCEHG) researchers unlikely clues about ground water in Wyoming.
The drilling began on October 7th and will continue until four boreholes extending to depths of 262 feet are dug in the Blair-Wallis area. Once these core samples are gathered, the drill crew will move to the Red Buttes area south of Laramie. Researchers hope the Red Buttes area cores will extend to over 900 feet.
Drilling began on October 7th at Blair-Wallis.
Photo Credit: Brady Flinchum

"Understanding groundwater in mountain regions is crucial so that we can estimate how much water will be available for use downstream," says Brady Flinchum, a geophysics graduate student and WyCEHG member at UW. But groundwater can be a tough thing to measure, particularly in the Laramie Range.

“As it turns out, the granite rock type in the Laramie Range makes it extra difficult to quantify groundwater because groundwater flow is concentrated into small fracture zones,” says Flinchum. Information gathered from these boreholes will allow WyCEHG geophysicists to “measure the properties that control the groundwater flow and storage in the subsurface and to determine the source of groundwater. We will be extracting water samples from different depths and using geochemistry to see if the water in the subsurface is the same as the rain water or stream water.”

According to Dr. Steve Holbrook, this project is a hugely important for WyCEHG. “A primary focus of our work is using geophysical imaging methods to infer subsurface material properties, including hydrological properties like porosity and fracturing. With the geophysical methods we can cover a lot of ground quickly, but to have confidence in our interpretations, we need to have some ground-truth data to calibrate our geophysical images against. 

"The drill holes currently being drilled in the Laramie Range will give us that ground truth and enable us to extrapolate known subsurface properties over the larger landscape."

Granite core offers clues into groundwater movement
Photo credit: Brady Flinchum

Holbrook has been working on getting the project in place for two years. He credits the support and cooperation of colleagues at the U.S. Forest Service in getting it off the ground.

Flinchum agrees with Holbrook on the significance of the drilling. “Scientists using geochemistry can learn about the source of the deep ground water from our samples, which is all part of the story of how water travels from the high mountains to the oceans.”


By Manasseh Franklin

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