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[SVC28-13] Dike inflation process below Sakurajima volcano during the earthquake swarm of 15 August 2015
Keywords:Dike, Earthquake Swarm, Sakurajima Volcano
An earthquake swarm associated with dike intrusion occurred beneath Sakurajima volcano on 15 August 2015. The hypocenters are distributed at depths of 0.3–1 km and 7:00–10:30, and at depths of 0.3–3 km and 10:30–12:00. At 12:00–24:00, the hypocenters are distributed in shallow and deep clusters at depths of 0.2–1 and 1.5–3.5 km, respectively. The T-axes of the deep cluster are distributed in the NW–SE direction. A 90° rotated pattern of strike-slip faulting is also observed at the deep cluster where the T-axes are distributed in the NE–SW direction. This reflects the change in the stress field due to the dike inflation during the earthquake generation, and indicates that the alteration of stress in the vicinity of the dike due to the dike inflation and VT earthquakes are induced by the stress exceeding the fracture strength of the rock. The results of this study are published in the following paper: Koike, M. and Nakamichi, H. (2021) Dike inflation process beneath Sakurajima volcano, Japan, during the earthquake swarm of August 15, 2015. Front. Earth Sci. doi:10.3389/feart.2020.600223. Please refer to the paper for details.