Many methods have been employed to observe earthquake precursors in the lithosphere, atmosphere, and ionosphere (Figure 1). Based on our progress and achievement, the current proposed project, iSTEP-4, consists of a main project and three sub-projects (Sub-project I: Seismo-ionospheric/atmospheric precursors, Sub-project II: Seismo-lithospheric precursors, Sub-project III: Statistics for earthquake hazard). The Main project operates the integrated ground-based seismo-electromagnetic observation system, including seven networks of magnetometers, infrasonic wave systems, atmospheric electric field mills, Doppler sounding systems, ionosondes, GPS receivers, and all sky cameras in Taiwan. Meanwhile the observed seismo-ionospheric precursors (SIPs), seismo-atmospheric precursors (SAPs), seismo-lithospheric precursors (SLPs) and statistical results from the subprojects will be compared with simulations of existing ionospheric physics models to find out possible causal mechanisms of the observed precursors.

Figure 1. An integrated study of seismo-lithospheric, atmospheric, and ionospheric precursors by means ground-based and satellite observations.