Airborne Geophysics for Improved Targeting of Groundwater and Geotechnical Drilling

Presented on Tuesday, December 3, 2019
Bill Brown1 and Flemming Efferso, Ph.D2, (1)SkyTEM Canada Inc, (2)SkyTEM Surveys ApS, Ayr, ON, Canada

Globally water resource management challenges have prompted the application of airborne electromagnetic methods (AEM). Increased usage of AEM to map water resources can be attributed to: 1) applicability of airborne methods to map electrical properties of the earth for geological interpretation, 2) advancements in both AEM that enable detection and interpretation of aquifer materials, and 3) the need for sustainable management of water resources worldwide. The application of AEM to solve a wide range of geotechnical engineering and environmental problems has also increased in recent years.

Characterizing depth to bedrock from sparse geotechnical drilling has risks and the consequences and faulty characterization can range from frustrating to catastrophic and costly. Drilling can also be slow, expensive and insufficient in terms of data coverage. The AEM method can map variations in the depth to bedrock and provide guidance for pre-engineering planning by determining expected excavation depths required, for example, for solid building foundations, pipeline routes or hydro power tunnels. In the same manner AEM can be applied to study the potential for landslides or failure of earthen dams and levees to identify weakness zones or sliding planes embedded in bedrock. Each of these solutions does not need a separate standalone airborne survey, rather, once collected a single data set can be interpreted for various targets, depths and objectives.

AEM data can characterize large and/or remote areas quicker and more economically than traditional methods and when combined with data inversion and statistical analysis can add to confidence in making earth management decisions. Significant cost reductions can be achieved by planning geotechnical drillings based on the preliminary geological model derived from AEM. Integrated with AEM, data available from drilling sites, even if limited in scope and coverage, can be linked and combined to create a model covering the complete area of interest.

Bill Brown
SkyTEM Canada Inc
Bill Brown is Regional Manager, North America, with SkyTEM Canada. Over the past 20 years Bill has developed a specific expertise in the applications of airborne time-domain and frequency domain geophysics for mapping mineral, energy, and water resources as well as for solutions for engineering and environmental problems. In the last 5 year Bill’s focus has been on groundwater mapping and he works with governments, consultants and private industry to provide technical and logistic solutions for challenging aquifer mapping programs. He has co-authored several papers and has been an invited speaker at many geophysical conferences. Bill has his MBA and provides entrepreneurs and new business owners with advice and inspiration as a mentor for the Waterloo Region Small Business Centre City.

Flemming Efferso, Ph.D
SkyTEM Surveys ApS, Ayr, ON, Canada
Dr. Flemming Effersø, Ph.D, is CEO of SkyTEM Surveys ApS, headquartered in Aarhus, Denmark. He has authored several papers on the application of geophysical methods for geotechnical and hydrogeological solutions. Dr. Effersø manages the company's development activities including working with research institutions and private companies to advance airborne geophysical technology.
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