Correcting for overburden thickness in airborne gravity data using electromagnetic data
5912427new methodology is introduced that corrects airborne gravity data for changes in thickness of glaciolacustrine overburden. The approach is tested for a 35 km-long line from the Quest-West survey in the interior plateau of British Columbia, Canada. A bedrock topography map was created by inverting helicopter transient electromagnetic data. The inversions were conducted independently every 25 m over a 73 × 32 km2 area including the line of interest using a 2-layer near-surface layered earth model and the depth to bedrock was interpolated across the area. The overburden and bedrock were assigned constant densities of 1.80 and 2.67 g/cm3, respectively. The gravity correction methodology employs the typical Bullard corrections with the additional step of using the bedrock topography map to correct for the gravitational acceleration contributed by changes in overburden thickness. Along the line of interest, the maximum overburden thickness reached approximately 300 m, corresponding to a gravity correction of up to 15 mGal.
|Conference||SEG New Orleans Annual Meeting, SEG 2015|
Caron, R. (Raymond), Samson, C, Bates, M. (Martin), & Chouteau, M. (Michel). (2015). Correcting for overburden thickness in airborne gravity data using electromagnetic data. In SEG Technical Program Expanded Abstracts (pp. 2022–2026). doi:10.1190/segam2015-5912427.1