Spatiotemporal Seismic Structure Variations Associated With the 2018 Kīlauea Eruption Based on Temporary Dense Geophone Arrays

Abstract

During the 2018 Kīlauea volcanic eruption, lava erupted from a series of new fissures in the lower East Rift Zone more than 30 km away from the summit through a dike intrusion. Between late May and early August, variations in the effusion rate at the persistent eruptive vent (Fissure 8) were observed following near-daily summit caldera collapse events. Targeting the ongoing eruptive activity and the subsurface magma movement, we deployed a temporary dense seismic array. The observed time-lapse changes in seismic velocity associated with the response of the summit collapse in three areas are presented in this study. The results show (1) clear spatially dependent co-collapse velocity reductions across the newly-intruded dike structure, (2) a gradual post-collapse velocity increase near Fissure 8 correlated with the surge of magma supply, and (3) a gradual post-collapse velocity increase on the summit likely associated with reservoir pressurization and crustal welding.