Studying hypothetical electromagnetic earthquake precursors using a global finite-difference time-domain model

Electromagnetic (EM) precursors may be detectable by satellites and ground-based stations before large earthquakes strike and destroy entire cities. However, earthquakes are near impossible to predict as the physics of earthquake precursors is still poorly understood. This paper reports a global finite-difference time-domain (FDTD) model to compute Maxwell's equations within the Earth-ionosphere cavity to better understand hypothetical earthquake precursors. A latitude-longitude space lattice accounts for the Earth's curvature, conductivity, and periodic boundary conditions for accurate extremely low frequency (ELF) and ultra-low frequency (ULF) wave propagation. Electric current excitations simulate a proposed earthquake precursor near the hypocenter of a 7.0 magnitude earthquake in Haiti in 2010. The resulting surface agneticfield demonstrates how current pulses diffuse through the Earth's lithosphere and reverberate in the ionosphere. The results can be further compared and correlated to ELF/ULF perturbations observed before earthquakes by satellites and ground-based stations.