Decrease in seismic velocity observed prior to the 2018 eruption of Kilauea volcano with ambient seismic noise interferometry

Abstract

The 2018 Kilauea eruption was a complex event that included deformation and eruption at the summit and along the middle and lower East Rift Zones. We use ambient seismic noise interferometry to measure time-lapse changes in seismic velocity of the volcanic edifice prior to the 2018 Kilauea Lower East Rift Zone eruption. Our results show that seismic velocities increase in relation to gradual inflation between 1 March and 20 April. In the ten days prior to the May 3rd eruption, a rapid seismic velocity decrease occurs even though the summit is still undergoing inflation. We show that inter-eruptive inflation/deflation is correlated with surface deformation, while the velocity decrease prior to East Rift Zone eruption is likely due to accumulating damage induced by the pressure exerted by the magma reservoir on the surrounding edifice. The accumulating damage and subsequent decrease in bulk edifice strength likely facilitates the transport of magma from the summit reservoir to the Middle East Rift Zone.