Analysis of Seismic Electromagnetic Phenomena Using the FDTD Method

Anomalous electromagnetic (EM) phenomena of the ultra-low frequency (ULF) and the extremely low frequency (ELF) prior to or during earthquakes are analyzed using the geodesic finite-difference time-domain (FDTD) algorithm and accurate geological EM data. Firstly, the underground EM eruption caused by the earthquake physical process is simulated, and its effects on the surface EM field are analyzed.Based on a series of simulations, a new explanation to the former observed ULF and ELF anomalies prior to and during earthquakes is proposed. Thereafter, to explain the enhancement of the Schumann resonances (SRs) observed in recent years, localized D-region ionospheric anomalies and background lightning noises are added simultaneously into the earthquake EM simulations, and the results are discussed. Finally, the general rules of seismic EM phenomena in the frequency range 0-40 Hz are summarized, and potential earthquake prediction methods are suggested.