Combined 3D Inversion of Ground and Airborne Electromagnetic Data over Iron Ore in Kiruna
M. Smirnova, N. Juhojuntti, M. Becken, M. Smirnov, P. Yogeshwar, A. Steuer, R. Rochlitz, M. Schiffler
Event name: 25th European Meeting of Environmental and Engineering Geophysics
Session: Geophysics for Geotechnics
Publication date: 11 September 2019
Info: Extended abstract, PDF ( 1.01Mb )
Price: € 20
We present the first results of a semi-airborne survey conducted in 2018 at Per Geijer iron ore in northern Sweden (Kiruna). In our semi-airborne system, the transmitter is positioned on the ground and magnetic field receivers are airborne. To support airborne measurements, we complemented the survey with an array of ground electric field receivers, magnetotelluric (MT) stations, and SMARTem measurements. The objective of the study is to combine different types of electromagnetic (EM) data in order to derive a common 3D conductivity model of the exploration area. We process data in frequency domain using a robust processing scheme. The airborne data are additionally corrected for rotation. The final 3D model is derived using combined ground and airborne data from three source positions (Controlled-Source EM inversion). Additionally, a 3D model from MT data is obtained separately and used as a starting model for CSEM inversion. Both models match the well-known surface geology and other geophysical information yet bring new insights into the general model of the camp. The next step is a joint inversion of the MT and semi-airborne CSEM data.