Japan Geoscience Union Meeting 2014

Presentation information

Oral

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

[S-VC52_28AM1] Mitigation of Volcanic disaster - Basic and applied research

Mon. Apr 28, 2014 10:00 AM - 10:45 AM 416 (4F)

Convener:*Kazutaka Mannen(Hot Springs Research Institute of Kanagawa Prefecture), Shinji Takarada(Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Eisuke Fujita(National research Instituite for Earth science and Disaster prevention, Volcanic research department), Hisashi Sasaki(Asia Air Survey Co., Ltd.), Chair:Shingo Takeuchi(Central Research Institute of Electric Power Industry, Civil Engineering Research Laboratory, Geosphere Sciences), Marekazu Ohno(Unzen Volcanic Area Geopark Promotion Council)

10:00 AM - 10:15 AM

[SVC52-01] Simulation of the Daisen-Kurayoshi tephra, in the San-in district, SW Japan, using Tephra2

*Takahiro YAMAMOTO1, Minoru SUGIYAMA2, Yasuhisa TAJIMA2 (1.Geological Survey of Japan, AIST, 2.Nippon Koei Co Ltd)

Keywords:Daisen-Kurayoshi tephra, Tephra2

The Daisen-Kurayoshi tephra, which erupted from Daisen volcano at about 53 ka, is one of the most voluminous Plinian fall deposits in Japan. Its apparent volume was estimated as more than 20 km3, but quantitative study of this tephra have not be done. So, we try to analyze this tephra using Tephra2 and decide its eruption parameters. In the simulation, we set 5 cases in height of the eruption column from 10 to 18 km, 4 cases in weight of the erupted magma from 1 to 8x10E+18 kg, 4 cases in medium grain size of the ejected materials from 0 to 3 phi, and 5 cases in sorting of the ejected material under the average wind data above Yonago. A total of 400 cases have been calculated. To explain the observed distribution of the tephra, the column height and ejecta weight have to be 18 km and 4 to 8x10E+18 kg (40 to 80 km3), respectively.