Subdivision of Seismicity Beneath the Summit Region of Kilauea Volcano: Implications for the Preparation Process of the 2018 Eruption

Abstract

AbstractLong‐period (LP), hybrid, and volcano‐tectonic (VT) seismicity are important indicators for tracking the evolution of volcanic processes. Here, we propose an unsupervised learning method to classify 5,949 seismic events in Kilauea volcano, Hawai'i, during a 4‐month period before the collapse of Pu'u’ O'o on April 30, 2018. The LPs and hybrids exhibit three major episodes, which progressively intensified and had increasing shallow events toward the eruption. The most intense episode starting 3 weeks before eruption coincides with changes in near‐caldera deformation and lava lake elevation in Halema'uma'u, serving as possible immediate precursors. However, the first two episodes imply magma migration was already active months prior to the eruption. The spatiotemporal patterns of abundant hybrids reveal that they are associated with magma movement but mixed with shear‐failure or near‐surface resonance. Our results provide useful constraints on the magmatic processes in the preparation phase of the Kilauea eruption in 2018.