[S-VC32] Active Volcanism

[SVC32-P26] Volcanic tremors associated with the 2010 phreatic eruptions of Shinmoedake volcano

*KOJI KATO¹ (1.Meteorological College)

Keywords:Phreatic eruption, Volcanic tremor

Shinmoedake volcano occurred subplinian eruption on January 26, 2011. Around December 2009, about a year before the eruption, wide-area GNSS began to detect changes indicating expansion several kilometers northwest of Mt. Shinmoedake, and between March and July 2010, small phreatic eruptions were repeated (Kato and Yamasato, 2013). Volcanic tremors were observed with these phreatic eruptions. The volcanic tremors associated with the eruption on May 27 can be roughly divided into a first part and a latter part based on amplitude. Both have peaks around 3 to 10 Hz, but the first part also has a slightly lower frequency component. In addition, compared with tilt records and camera images, the first part generally corresponds to the expansion phase, and the latter part corresponds to the contraction phase and eruption. The source of this volcanic tremor was estimated using the amplitude of each observation point, based on the method of Ichihara and Matsumoto (2017). In this presentation, we report on the estimation of the source of the volcanic tremor associated with the phreatic eruption of Shinmoedake in 2010, and the consideration of the eruption process by comparing it with other observations.
This study was funded by Earthquake Res. Inst., the University of Tokyo, Joint Research program 2024-D-07.