Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

S (Solid Earth Sciences) » S-VC Volcanology

[S-VC41] Active Volcanism

Mon. May 21, 2018 1:45 PM - 3:15 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:Nishimura Takeshi, Maeno Fukashi

1:45 PM - 2:00 PM

[SVC41-01] Volcanic eruptions and moderate earthquakes

*Takeshi Nishimura1 (1.Department of Geophysics, Graduate School of Science, Tohoku University)

Keywords:volcanic eruptions, earthquake, interaction

It is well known that seismic activities increase around volcanoes before eruptions a (e.g., Benoit and McNutt, 1996). These activities of earthquakes, which have been well investigated at each volcano, are considered to be caused by magma migration, activation of hot water beneath volcanoes. The present study systematically researches the changes in seismicity around volcanoes using reliable recent data catalog of earthquakes and volcanic eruptions. CMT solutions and Smithsonian records of volcanic eruptions are used. Earthquakes with a magnitude larger than or equal to 5 for the period from 1976 to 2015 are analyzed. Eruptions with a VEI larger than or equal to 2 for the period from 1981-2010 are examined. The results show that the earthquakes with a magnitude ranging from 5 to 6 likely occur on the same day or for a few tens of days after eruptions locating within 50 km from the volcanoes while the seismicity more than 50 km far from the volcanoes does not significantly change. For the eruption continuing more than about a month, the number of earthquakes increases for about three years after the end of eruption. Also, the seismicity seems to be activated from about 1 year before eruptions. Since large earthquakes trigger eruptions at nearby volcanoes (Nishimura, 2017), these results strongly suggest interactions between earthquakes and eruptions.