This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
This Major Research Instrumentation Recovery and Reinvestment (MRI-R2) Program grant supports acquisition of optical and acoustic borehole visualization tools to facilitate characterization of subsurface sedimentary features, fractures, and dissolution features in hydrological studies and resource assessments for the State of Wisconsin. The requested imaging tools would be part of an established subsurface investigations program undertaken by Wisconsin Geological and Natural History Survey (WGNHS) scientists and staff. The WGNHS is a special-mission unit of the University of Wisconsin-Extension, and undertakes research, resource evaluation, teaching, and outreach related to the water, rocks, and minerals of Wisconsin. Survey scientists conduct their own research but also collaborate with universities, state and federal agencies, communities, and the private sector throughout and beyond Wisconsin. The PIs of the proposal hold affiliate appointments with and are active participants in the hydrogeology program at the University of Wisconsin-Madison. WGNHS scientists also collaborate with regional faculty and their students from other UW campuses such as UW-Milwaukee, UW-Oshkosh, UW-Green Bay and UW-Stevens Point, as well as other regional institutions including Beloit College. The equipment would also support collaborative projects between WGNHS scientists and U.S. Geological Survey, Wisconsin Department of Natural Resources, Wisconsin Department of Agriculture, Wisconsin counties, and other agencies. Borehole televiewers to be acquired will support a range of scientific research themes including fractured rock hydrogeology, contaminated water transport, aquitard hydrogeology and groundwater resources of broad local, national, and international interest.
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The geophysical imaging tools acquired under this project have significantly enhanced the ability of the Wisconsin Geological and Natural History Survey (WGNHS) to evaluate the geology and hydrogeology of Wisconsin and to conduct research on bedrock hydrogeology. Downhole geophysical imaging tools are lowered up and down open wells or boreholes using a thin cable. The Optical Borehole Imager (OBI) tool collects a 360o digital optical image of the borehole wall. The Acoustic Borehole Imager (ABI) tool collects a similar image using acoustic energy instead of light. Both tools transmit the data through the cable to a surface unit and computer for digital processing using specialized software purchased under this equipment grant. Both tools also collect directional data (magnetic north and inclination) so the images can be precisely oriented in space. This means that WGNHS scientists can use the tool to locate both the depth and orientation of small features like fractures and crossbeds hundreds of feet below the surface. The attached images show examples of fractures imaged by the optical borehole tool. The tools are currently being used in a study of the transport of human viruses to municipal drinking water wells in southern Wisconsin. Viruses can move rapidly through fractures and other discrete discontinuities in the subsurface. Detecting these features is important for understanding how to protect wells from contamination, and the imaging tools produce ideal data for such work. The imaging tools and associated software are also being used by WGNHS scientists in efforts to better understand the distribution and geologic history of bedrock units across Wisconsin. Most of these bedrock formations form aquifers used for water supply, and understanding these units is important for water supply planning and management. Graduate and undergraduate geoscience students become familiar with the use of these tools and interpretation of the resulting data through field courses and participation in WGNHS projects. The tools are also used in short courses aimed at practicing professionals in the water resources and regulatory fields and conducted by WGNHS scientists.
