We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Combined Inversion of Airborne Electromagneticand Static Magnetic Field Data.
- Authors
Pirttijärvi, Markku; Zaher, Mohammed A.; Korja, Toivo
- Abstract
The frequency domain airborne electromagnetic (AEM) data of the Geological Survey of Finland (GTK) is transformed into apparent resistivity because it's geologically and physically more meaningful and easier to comprehend than the in-phase and quadrature component of the original data. The traditional transformation method based on a model of homogeneous conductive half-space has two main problems: a) conductive sediment layers makes the bedrock appear more conductive and b) the signreversals of the in-phase component due to magnetized rocks that cannot be modelled without taking the magnetic susceptibility (or permeability) into account. We present a combined inversion method designed for the AEM and magnetic profile data of GTK. The inversion method uses a two-layer model for AEM data and a stack of vertical magnetized prisms for magnetic data. Laterally constrained inversion is used where the parameter variations between neighbouring points are minimized together with data misfit. We show that it is possible to resolve the four unknown model parameters (resistivity and thickness of the overburden, resistivity and magnetic susceptibility of the basement) even from single frequency AEM data. Moreover, we show that the combined inversion yields improved estimates for bedrock resistivity. In addition to the conductance of the overburden and the resistivity of bedrock, the combined inversion gives realistic estimates for magnetic susceptibility allowing cross-correlation of the sources of conductivity and magnetic anomalies. The efficacy of the inversion method is demonstrated using GTK's airborne data from two example areas
- Subjects
MAGNETIC susceptibility measurement; ELECTRICAL resistivity; SEISMIC traveltime inversion; RADIOACTIVITY measurements; CESSNA 208 (Turboprop transport)
- Publication
Geophysica, 2014, Vol 50, Issue 2, p65
- ISSN
0367-4231
- Publication type
Article