3-D Modeling of Layered Earth Structure in the Geothermal Systems Using Time Domain Electromagnetics (TDEM) Method

3-D TDEM modeling has been successfully conducted to map the structure of layered Earth based on the value of resistivity. 3-D analysis required to observe propagation and interaction of electromagnetic fields with the material below the Earth's surface in the z-axis direction. The problem in electromagnetic modeling for geophysical exploration activities is discretizing of medium for electromagnetic wave propagation. In this modeling use Finite Difference Time Domain (FDTD) method because it can solve electromagnetic field interaction problem and to analyze the transient electromagnetic method compared to the frequency domain. The first step in this method is positioning of the cell to the lines of the magnetic fields that surround normal electric field line, so that this condition is suitable with the components of curl operation of Ampere's law. Conclusion of this modeling results indication that utilizing TDEM method in the exploration activities is very essential and useful to map the resistivity distribution in the layered Earth. The resistivity is one of physical properties that can describe the structure of the layered Earth to determine the potential reservoir of geothermal systems as the renewable energy. (paper)