| Title | A COMBINED APPLICATION OF HIGH-RESOLUTION THERMAL INFRARED AND MAGNETIC DRONE-BASED SURVEYS OVER LARGE AREAS FOR GEOTHERMAL AND ELEMENT EXPLORATION IN WESTERN CANADA |
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| Authors | M. Eyre, J. Zheng, D. Alonso-Torres, F. Heikkinen, R. Metge, H. Alvarez, A. Thompson, T. Thompson |
| Year | 2019 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Drone, UAV, geophysics, magnetics, thermal infrared, geothermal, Canada |
| Abstract | In Canada, geothermal and element exploration is challenging due to thick vegetation cover, steep topography, and the presence of hundreds of meters of glacial overburden masking geothermal expressions. Consequently, unique exploration techniques sometimes need to be deployed. Remote sensing thermal infrared surveys and magnetic surveys can be a useful tool for mapping geothermal anomalies and thus aid in characterizing the underlying geothermal system. However, the resolution-to-cost relationship of airborne/satellite surveys often do not match the needs for geothermal prospecting over a large area. In November 2018, Borealis GeoPower employed an unmanned aerial vehicle (UAV or drone) to conduct the first combined drone-based thermal and magnetic survey over a ~22 km2 area to investigate their Terrace, British Columbia, geothermal project, located near the hottest hot spring in Canada. Over 47,000 georeferenced thermal images were taken; image processing techniques were consequently applied to orthorectify and mosaic the images to obtain a thermal map with sub-meter (~0.5 m) resolution. The high-resolution of the magnetic data enabled enhanced mapping of small magnetic features that would typically go undetected in surveys with lesser resolution. The combination of drone-based thermal and aeromagnetic surveys effectively identified unreported geothermal outflows and subsurface geological structures, demonstrating the usefulness of these techniques for geothermal exploration. |