Large-Scale, High-Resolution Drone-Based Thermal Infrared and Magnetic Surveys for Geothermal and Element Exploration in Western Canada

Abstract

Geothermal and element exploration in Canada can be challenging due to the presence of hundreds of meters of glacial overburden masking geothermal expressions, therefore 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 of airborne/satellite surveys often does not match the needs for geothermal prospecting over a large area. In November 2018, we employed an unmanned aerial vehicle (UAV or drone) thermal infrared survey and magnetic survey over a ~22 square-km area to investigate our 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. In this paper we demonstrate the usefulness of obtaining large-scale, high-resolution, drone-based surveys to assess geothermal prospects in a fast, efficient and relatively low-cost manner.