Commonly-used time domain electromagnetic method for exploration employ coil or loop as receiver measuring magnetic field related B-field or dB/dt. Since the electric (E-) and magnetic (H-) fields are physically symmetric in Maxwell’s Equations and thus must be equally informative, we are trying to develop a new exploration technique called “E-field Time Domain Electromagnetic Method”. This method will work in time domain with transient waveform in inductive transmitter loop and measure the electric field by grounded electrodes. Some preliminary studies have shown that E-field measurements are sensitive to alteration and have large penetration into the earth so that more information can be supplied to geologists for interpretation and decision making. The key aspects of my thesis research will include:
- forward modeling of E-field source and measurement in time domain with some typical deposit models; analysis of E-field sensitivity; summary of pros and cons of E-field;
- quantitative interpretation of E-field data using advanced 3D TEM inversion techniques; producing code and utility to obtain 3D structure of conductivity;
- survey design for an E-field TEM survey;
- optimization of workflow for practical inversion of E-field TEM;
- comparison between E-field TEM and H-field TEM in all technical aspects; conclusion of Efield and H-field behavior in time domain for the purpose of exploration;
- field data application.