Petrophysical measurements of rock samples collected within the Haast, Torlesse, and Alpine Fault Zone terranes of the South Island of New Zealand indicate significant seismic P-wave velocity anisotropy at pressures representing depths of up to 30 km. The percentage of anisotropy increases with increasing metamorphic grade and thus decreases with structural distance from the Alpine Fault. A maximum anisotropy of 17.3% was obtained from a drillcore sample located within the garnet-oligoclase zone schist, immediately adjacent to the Alpine Fault. Shear-wave splitting is another important property of the schists. For propagation parallel to foliation, split shear waves show velocity differences up to 1 km/s. At elevated pressures, the measured seismic velocity anisotropy is caused by preferred mineral orientation and is not due to the presence of cracks. The pronounced velocity anisotropy will significantly affect propagating seismic waves collected during both natural and active source seismic experiments; this effect must be incorporated into the analyses of such seismic data.

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We present finite‐difference simulation results that lend new insight into the behavior of multicomponent induction logging tools when in the presence of anisotropic layers, boreholes, and invasion zones. We use four independent models to investigate multicomponent tool properties as well as typical magnetic field responses. In addition, model variations with respect to formation dip angle, layer geometry, and conductivity provide data about the effects of geological variation on the multicomponent responses. Simulations suggest a coaxial tool configuration senses a depth of twice the source–receiver offset, although this depth is reduced to the source–receiver offset with coplanar configurations. Numerical responses in the presence of transversely isotropic layers provide evidence that anisotropy can have a measurable effect on both coaxial and coplanar magnetic fields; these effects increase as layer dip increases. Sensitivity analyses substantiate these numerical results. An investigation of tool responses to varying borehole and invasion zone conductivities and diameters demonstrates that the coplanar tool orientation is much more sensitive to near‐borehole variations than the coaxial configuration. A frequency‐differencing technique is presented to mitigate unwanted borehole‐induced bias in multicomponent data; however, drawbacks include decreased signal strength and possible geological signal destruction.

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