Joint quantitative interpretation of electrial and seismic anisotropy: Relation between olivine LPO by solid-state deformation in the upper mantle and the resulting bulk electrical properties

• Applicant: Dr. Alexander Gatzemeier
• Subject Area: Geophysics
• Term: from 2003 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5401900

Seismic anisotropy measured by the splitting of teleseismic shear waves is used to investigate the upper mantle deformation. Unfortunately this SKS splitting technique has a poor vertical resolution and therefore tectonic interpretations are open to questions. Electrical properties investigations, such as magnetotelluric (MT) soundings, are another source of information on the upper mantle structure. Assuming that the electrical strike (direction of highest conductance) obtained by long-period MT soundings is correlated with the orientation of the olivine a-axis, there is another method to probe the crystallographic orientation of olivine and, hence, the flow patterns in the upper mantle. By a joint interpretation of electrical and seismic anisotropy is not straightforward. Although the electrical properties of single-crystals and isotropic polycrystalline olivine aggregates are well understood, there has been no work on the relation between deformation in the upper mantle and the resulting electrical properties. To combine observed electrical and seismic anisotropy data electrical properties should be included in existing forward numerical modelling to investigate the effect of mantle deformation on electrical properties.

• DFG Programme: Research Fellowships