Very-low-frequency electromagnetic (VLF-EM) measurements in the Schirmacheroasen area, East Antarctica

To assess the feasibility of the very-low-frequency electromagnetic (VLF-EM) method in the Schirmacheroasen area of East Antarctica, and to investigate its response, VLF-EM measurements were performed along four traverses. The preliminary results reveal the locations of geological boundaries and shear zones/faults, which may indicate that VLF anomalies are due to shear zones or alteration zones located along contacts between different rock types. The strength of the VLF anomaly decreases over the polar ice cap. The inphase component of the VLF anomaly, when processed and interpreted with an analytic signal approach, yields a depth range of 15-30. m, whereas Fraser and Hjelt filter analyses yield a depth range of 25-60. m. The VLF-EM responses along all four traverses, along with their interpretations, are presented here as a case study.