1996/02/01 by Richard S. Smith, Jan Klein, Jan J. Klein · 2 citations
Earth and Planetary Sciences · Engineering · #Geophysical and Geoelectrical Methods #Geophysical Methods and Applications #Seismic Waves and Analysis
paper · doi:10.1190/1.1443957
Abstract Airborne induced-polarization (IP) measurements can be obtained with standard time-domain airborne electromagnetic (EM) equipment, but only in the limited circumstances when the ground is sufficiently resistive that the normal EM response is small and when the polarizability of the ground is sufficiently large that the IP response can dominate the EM response. Further, the dispersion in conductivity must be within the bandwidth of the EM system. One example of what is hypothesized to be IP effects are the negative transients observed on a GEOTEM survey in the high arctic of Canada. The dispersion in conductivity required to explain the data is very large, but is not inconsistent with some laboratory measurements. Whether the dispersion is caused by an electrolytic or dielectric polarization is not clear from the limited ground follow-up, but in either case the polarization can be considered to be induced by eddy currents associated with the EM response of the ground. If IP effects are the cause of the negative transients in the GEOTEM data, then the data can be used to estimate the polarizabilities in the area.