Volcanic history and debris flow occurrence process of Mt Fuji

• Project/Area Number: 16510134
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Natural disaster science
• Research Institution: Hokkaido University (2006); The University of Tokyo (2004-2005)
• Principal Investigator: YOSHIMOTO Mitsuhiro Hokkaido Univ., Faculty of Science, Research Associate, 大学院理学研究院, 助手 (20334287)
• Co-Investigator(Kenkyū-buntansha): KANEKO Takayuki Univ. of Tokyo, Earthquake Research Inst., Research Associate, 地震研究所, 助手 (90221887) ; FUJII Toshitsugu Univ. of Tokyo, Earthquake Research Inst., Professor, 地震研究所, 教授 (00092320)
• Project Period (FY): 2004 – 2006
• Project Status: Completed (Fiscal Year 2006)
• Budget Amount: ¥2,600,000 (Direct Cost: ¥2,600,000); Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000); Fiscal Year 2005: ¥800,000 (Direct Cost: ¥800,000); Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: Fuji volcano / Volcanic History / Mud flow / Boring core / 土石流 / 火山帯形成史

Research Abstract

Mt. Fuji is a composite stratovolcano consisting of four volcanoes; Pre-Komitake, Komitake, Ko-Fuji (Old Fuji) and Shin-Fuji (Young Fuji) volcanoes in order of decreasing age. The Aim of this study was to obtain volcanic history of Mt Fuji using the core samples drilled at northeastern flank of the volcano by ERI, Univ. of Tokyo in 2001-2003.
In the drilled cores, hornblende-bearing andesite and dacite together with basalt were found as lava flows and fragments in mud flows below the Komitake volcanic rocks which contain olivine-bearing plagioclase-phyric two-pyroxene basaltic andesite (51-53 % SiO2). The volcano whose activity produced these basalt to dacite (50-70 % SiO2) was called pre-Komitake Volcano. As a thin soil layer was found just above the pre-Komitake volcanic rocks, the activity of Komitake volcano started after a short depositional hiatus following that of pre-Komitake Volcano. It ended its activity about 100 ka roughly together with that Ashitaka Volcano. Subsequently, Fuji Volcano shifted the activity center south of Komitake Volcano and huge amount of basaltic ejecta were issued.
Deposits of eastern flank of Ko-Fuji volcano before 30ka composed mainly of mudflow deposit derived from scoria fall, in contrast to scoria fall deposit after 30ka.It is possible that those conversion of deposit was caused by existence of summit glacier associated with climate change.

Research Products

• [Journal Article] 先富士火山群 (2007)
  • Author(s): 中田節也, 吉本充宏, 藤井敏嗣
  • Journal Title: 富士火山(荒牧重雄, 藤井敏嗣, 中田節也, 宮地直道編)(山梨県環境科学研究所) Pages: 69-77
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 富士火山北東斜面で発生した2,000年前以降の火砕丘崩壊型の火砕流 (2007)
  • Author(s): 田島靖久, 宮地直道, 吉本充宏, 阿部徳和, 千葉達朗
  • Journal Title: 富士火山(荒牧重雄, 藤井敏嗣, 中田節也, 宮地直道編)(山梨県環境科学研究所) Pages: 256-267
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Pre-Fuji Volcanoes (2007)
  • Author(s): Nakada, S., Yoshimoto, M., Fujii, T.
  • Journal Title: Fuji volcano, Yamanashi Institute of Environmental Sciences Aramaki, S., Fujii, T., Nakada, S. and Miyaji, N eds) Pages: 69-77
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Pyroclastic flows originated from the collapse of scoria cones for the last 2,000 years on the north eastern slope of Fuji volcano (2007)
  • Author(s): Tajima, Y., Miyaji, N., Yoshimoto, M.Abe, N., Chiba, T.
  • Journal Title: Fuji volcano, Yamanashi Institute of Environmental Sciences (Aramaki, S., Fujii, T., Nakada, S. and Miyaji, N eds) Pages: 255-267
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] 掘削試料から見た富士山の火山形成史 (2004)
  • Author(s): 吉本充宏, 金子隆之, 嶋野岳人, 安田敦, 中田節也, 藤井敏嗣
  • Journal Title: 月刊地球 号外48 Pages: 89-94
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 富士火山北東斜面の火砕流堆積物の特徴 (2004)
  • Author(s): 吉本充宏, 金子隆之, 藤井敏嗣, 中田節也
  • Journal Title: 月刊地球 号外48 Pages: 124-130
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 富士山東斜面におけるテフラ層序-掘削の成果と活動史- (2004)
  • Author(s): 金子隆之, 吉本充宏, 嶋野岳人, 安田敦, 藤井敏嗣, 中田節也, 上杉陽
  • Journal Title: 月刊地球 号外48 Pages: 101-107
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 富士火山のマグマの特質とマグマ供給系-テフラ層の分析による検討- (2004)
  • Author(s): 金子隆之, 安田敦, 吉本充宏, 嶋野岳人, 藤井敏嗣, 中田節也
  • Journal Title: 月刊地球 号外48 Pages: 146-152
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 溶岩流試料に基づくマグマの成因の検討 (2004)
  • Author(s): 安田敦, 金子隆之, 吉本充宏, 嶋野岳人, 中田節也, 藤井敏嗣
  • Journal Title: 月刊地球 号外48 Pages: 139-145
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Volcanic history of Fuji volcanoes based on scientific drilling results (2004)
  • Author(s): Yoshimoto, M.Kaneko, T., Shimano, T., Yasuda, A., Nakada, S., Fujii, T.
  • Journal Title: Chikyu Monthly 48 Pages: 89-94
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Characteristics of pyroclastic flow deposits on the northeastern flank of Fuji volcano, Japan (2004)
  • Author(s): Yoshimoto, M.Kaneko, T., Nakada, S., Fujii, T.
  • Journal Title: Chikyu Monthly 48 Pages: 124-130
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Stratigrahic study of tephra on the eastern slope of Mt Fuji : Results of scientific drilling and the volcano development of history (2004)
  • Author(s): Kaneko, T., Yoshimoto, M.Shimano, T., Yasuda, A., Fujii, T., Nakada, S., Uesugi, Y.
  • Journal Title: Chikyu Monthly 48 Pages: 101-107
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Magmatic features and the plumbing system of Mt Fuji : a chemical study of scoria fall layers (2004)
  • Author(s): Kaneko, T., Yasuda, A., Yoshimoto, M.Shimano, T., Fujii, T., Nakada, S.
  • Journal Title: Chikyu Monthly 48 Pages: 101-107
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Petrological study on the plumbing system of Mt. Fuji based on lava-flows drilled at FJ 1-3 bore-sites (2004)
  • Author(s): Yasuda, A., Kaneko, T., Yoshimoto, M.Shimano, T., Nakada, S., Fujii, T.
  • Journal Title: Chikyu Monthly 48 Pages: 48-48
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] 富士山東斜面におけるテフラ層序-掘削の成果と活動史- (2004)
  • Author(s): 金子隆之, 吉本充宏, 嶋野岳人, 安田 敦, 藤井敏嗣, 中田節也, 上杉陽
  • Journal Title: 月刊地球 号外48 Pages: 101-107