Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

S (Solid Earth Sciences) » S-VC Volcanology

[S-VC41] Active Volcanism

Tue. May 22, 2018 3:30 PM - 5:00 PM Convention Hall A (CH-A) (2F International Conference Hall, Makuhari Messe)

convener:Yuta Maeda(Nagoya University), Takahiro Miwa(National research institute for earth science and disaster prevention), Yosuke Aoki(東京大学地震研究所, 共同), Takeshi Nishimura(Department of Geophysics, Graduate School of Science, Tohoku University), Takahiro Ohkura(Aso Volcanological Laboratory, Institute for Geothermal Sciences, Graduate School of Science, Kyoto University), Satoshi Okumura(Division of Earth and Planetary Materials Science, Department of Earth Science, Graduate School of Science, Tohoku University), Tomofumi Kozono(Department of Geophysics, Graduate School of Science, Tohoku University), Chairperson:Tameguri Takeshi, Kazama Takahito

4:15 PM - 4:30 PM

[SVC41-34] Monotonic volcanic tremor at Sakurajima volcano, August, 2017

*Eisuke Fujita1 (1.National research Instituite for Earth science and Disaster Resilience, Volcanic research department)

Keywords:volcanic tremor, Sakurajima

Monotonic volcanic tremor was observed from Aug. 22 to Aug. 25, 2017, at Sakurajima volcano japan. This tremor is triggered by an impulsive high-frequency event, and monotonic component follows about several seconds in general. The monotonic volcanic tremor is observed with the interval about 10 – 20 minutes. Infrasonic wave is also observed at the initial phase, suggesting the explosive triggering.

The frequency spectra suggest one or a few characteristic frequencies, which varies in different periods. Their waveform characteristics show both simple monotonic one, and in some case, indicate a system with limit-cycle.

From the visual observation, this volcanic tremor is associated with chugging at the Showa crater, and in some cases, the signal is audible. Their source locations are determined around shallow beneath Showa crater by amplitude-decay method. This volcanic tremor is suggestive to recognize the liquid-gas system beneath the crater at Sakurajima.