Shinmoe-dake volcano, which is within the Kirishima volcanic complex, Japan, erupted from March to June 2018. The eruptions were recorded by various geophysical instruments that were installed 3.1–5.4 km from the crater. Here we present the first documented evidence of infrasound-induced electric-field changes in the near surface at the time of the explosive eruptions. Significant electric-field changes coincide with the infrasound arrivals. An order-of-magnitude estimation of the electric field indicates that the electrokinetic mechanism induced by pore water movement relative to the host rock, is a plausible cause of the observed infrasound–electric-field coupling. The ground displacement and electric-field particle motions suggest that the infrasound waves from the explosive eruptions produce vertical ground motion, and simultaneously induce horizontal groundwater flow, which subsequently generates electric-field changes due to the propagation of the infrasound wave.
All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)