Transient electromagnetic surveys for highresolution near-surface exploration: basics and case studies
M.V. Sharlov, I.V. Buddo, N.V. Misyurkeeva, I.A. Shelokhov and Yu.A. Agafonov
Journal name: First Break
Issue: Vol 35, No 9, September 2017 pp. 63 - 71
Special topic: EM/Potential Methods
Info: Article, PDF ( 1.06Mb )
Transient electromagnetic (TEM) surveys have been used broadly in Russia and worldwide for engineering geology, groundwater prospecting, and other near-surface applications (Bucharsky et al., 1986; Plotnikov and Kozhevnikov, 2004; Agafonov et al., 2013; Ranieri et al., 2005; Shaaban et al., 2016, etc.), as well as for petroleum and mineral exploration (Mandelbaum et al., 1983; Korolkov, 1987; McNeill, 1980). Voltage decay patterns are highly sensitive to the presence of conductors associated with ore bodies, water saturation, clay, etc. Another advantage of the method is that it does not need galvanic grounding and works in any climate and terrain. The resolution of shallow transient electromagnetic (sTEM) data has improved greatly in the past two decades due to breakthrough in micro-electronics providing advanced facilities for data acquisition and processing (nanosecond sampling rates, high-resolution ADC, etc.). Extensive sTEM surveys at a density reaching 33 points per km2 have demonstrated high performance in solving diverse problems of geosciences from structural mapping to environmental monitoring within a range of depths from 10 to 500-600 m.