Japan Geoscience Union Meeting 2016

Presentation information


Symbol S (Solid Earth Sciences) » S-VC Volcanology

[S-VC47] Active volcanism

Tue. May 24, 2016 3:30 PM - 5:00 PM Convention Hall B (2F)

Convener:*Yosuke Aoki(Earthquake Research Institute, University of Tokyo), Yuta Maeda(Nagoya University), Chair:Hiroshi Shinohara(Geological Survey of Japan, AIST), Takeshi Tameguri(Sakurajima Volcano Research Center,Disaster Prevention Research Institute, Kyoto University)

4:45 PM - 5:00 PM

[SVC47-12] Detection of abrupt increase in CO2 flux from a submarine volcano, Wakamiko, in the innermost par of Kagoshima Bay in July 2015

*Toshiro Yamanaka1, Kazuna Kondo1, Mari Kobayashi1, Takuro Noguchi2, Kei Okamura3, Tomoko Yamamoto4, Urumu Tsunogai5, Jun-ichiro Ishibashi6 (1.Graduate School of Natural Science and Technology, Okayama University, 2.Multidisciplinary Science Cluster, Research and Education Faculty, Kochi University, 3.Center for Advanced Marine Core Research, Kochi University, 4.Faculty of Fisheries, Kagoshima University, 5.Graduate School of Environmental Studies, Nagoya University, 6.Graduate School of Science, Kyushu University)

Keywords:Wakamiko submarine volcano, CO2 flux, Volcanic activity of Sakurajima Volcano

CO2 flux from a submarine volcano, Wakamiko, Southern Kyushu, Japan, has been measured since 2007. The CO2 flux from the volcano were varied ranging from 160 to 360 ton/day from 2007 to 2014, but in 2015 the flux is significantly increased up to 500 ton/day calculated using the data obtained in July. In the next month, August 2015, significant volcanic tremors were started beneath Sakurajima Volcano, so large-scale eruption of the volcano had been expected. After that, volcanic tremors beneath Sakurajima Volcano declined within two weeks, and also CO2 flux from Wakamiko Volcano observed in December was decreased to similar range before 2014. Magma chamber beneath Aira Caldera has been considered to provide magmatic volatile to Wakamiko Volcano and to be connected with another shallower magma chamber beneath Sakurajima Volcano. The volcanic tremors were considered to be associated with ascending of magma from the shallower magma chamber. Therefore, the detected abrupt increase of CO2 flux from Wakamiko Volcano may reflect those magma activities.