Effect of geomagnetic intensity on the atmospheric 14C variation

• Project/Area Number: 25800249
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Kumamoto University
• Principal Investigator: Mochizuki Nobutatsu 熊本大学, 大学院先導機構, 准教授 (60422549)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2014: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000); Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
• Keywords: 古地磁気強度 / 宇宙線生成核種 / 放射性炭素濃度 / 富士火山 / 阿蘇火山 / 放射性炭素 / 炭素年代

Outline of Final Research Achievements

The present study attempts to obtain reliable paleointensities from 14C dated lava flows and then discuss the relationship between the absolute paleointensity and atmospheric 14C. We sampled ten lava flows of 4-30 ka 14C ages of Fuji and Aso Volcanoes in Japan. These 14C ages were reported from the charred material in/below the lava flows or organic sediment below the lava flows in previous studies. Seventy-six samples were subjected to the LTD-DHT Shaw paleointensty experiment (Tsunakawa-Shaw experiment), and 64 of them passed the selection criteria. Consistency of paleointensity estimates was recognized for seven sites of six lava flows and the mean values were adopted as paleointensities. These paleointensity data and the 14C data reported for the same lava flows give a constraint on the relationship between virtual axial dipole moment and the atmospheric 14C.

Research Products

• [Journal Article] Pressure effect on magnetic hysteresis parameters of single-domain magnetite contained in natural plagioclase crystal (2015)
  • Author(s): Sato, Masahiko; Yamamoto, Yuhji; Nishioka, Takashi; Kodama, Kazuto; Mochizuki, Nobutatsu; Usui, Yoichi; Tsunakawa, Hideo
  • Journal Title: GEOPHYSICAL JOURNAL INTERNATIONAL Volume: 202 Issue: 1 Pages: 394-401
  • DOI: 10.1093/gji/ggv154
  • Peer Reviewed
• [Journal Article] High Resolution Magnetic Structure of Active Hydrothermal Systems in the Back-Arc Spreading Region of the Southern Mariana Trough (2015)
  • Author(s): Fujii M., K. Okino, C. Honsho, J. Dyment, S. Florent, N. Mochizuki, M. Asada
  • Journal Title: Journal of Geophysical Research: Solid Earth Volume: 120 Issue: 5 Pages: 2821-2837
  • DOI: 10.1002/2014jb011714
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Basic properties of transition remanent magnetizations of magnetite in relation to the ambient field using granite samples (2015)
  • Author(s): Sato, M., K. Seita, T. Miyagawa, N. Mochizuki, T. Kogiso, H. Tsunakawa
  • Journal Title: Geophys. J. Int. Volume: 200 Issue: 1 Pages: 25-34
  • DOI: 10.1093/gji/ggu371
  • Peer Reviewed
• [Journal Article] Hydrostatic pressure effect on magnetic hysteresis parameters of multidomain magnetite: Implication for crustal magnetization (2014)
  • Author(s): Sato, Masahiko; Yamamoto, Yuhji; Nishioka, Takashi; Kodama, Kazuto; Mochizuki, Nobutatsu; Tsunakawa, Hideo
  • Journal Title: PHYSICS OF THE EARTH AND PLANETARY INTERIORS Volume: 233 Pages: 33-40
  • DOI: 10.1016/j.pepi.2014.06.001
  • Peer Reviewed
• [Journal Article] 絶対古地磁気強度とテフロクロノロジー： 相対古地磁気強度変動曲線の絶対値較正へ向けて (2014)
  • Author(s): 望月伸竜
  • Journal Title: 号外地球 Volume: 63 Pages: 130-135
• [Journal Article] Multi-level consistencytests in paleointensity determinationsfrom the welded tuffs of the Asopyroclastic-flow deposits, 掲 載 決 定 (2013)
  • Author(s): Mochizuki, N., T. Maruuchi, Y. Yamamoto,and H. Shibuya
  • Journal Title: Phys. Earth Planet. Inter. Volume: 223 Pages: 40-54
  • DOI: 10.1016/j.pepi.2013.05.001
  • Peer Reviewed
• [Presentation] Paleointensity determination of welded tuffs extruded with tephra layers: A new approach to calibration of relative paleointensity stacks (2015)
  • Author(s): Mochizuki, N., S. Fujii, T. Hasegawa, Y. Yamamoto, T. Hatakeyama, M. Okada, H. Shibuya
  • Organizer: 2015 AGU Fall Meeting
  • Place of Presentation: サンフランシスコ（米国）
  • Year and Date: 2015-12-14
  • Int'l Joint Research
• [Presentation] Tsunakawa-Shaw method - an absolute paleointensity technique using alternating field demagnetization (2015)
  • Author(s): Yamamoto, Y., N. Mochizuki, H. Shibuya, H. Tsunakawa
  • Organizer: 2015 AGU Fall Meeting
  • Place of Presentation: サンフランシスコ（米国）
  • Year and Date: 2015-12-14
  • Int'l Joint Research / Invited
• [Presentation] 富士火山溶岩による絶対古地磁気強度測定：古地磁気強度と大気の放射性炭素の関係性 (2015)
  • Author(s): 望月伸竜，佐藤雅彦
  • Organizer: 地球電磁気・地球惑星圏学会第138回講演会
  • Place of Presentation: 東京大学（東京都）
  • Year and Date: 2015-10-31
• [Presentation] 絶対古地磁気強度とテフロクロノロジー： 相対古地磁気強度変動曲線の絶対較正 (2015)
  • Author(s): 望月伸竜，藤井哲夢，長谷川健，岡田誠，渋谷秀敏
  • Organizer: 日本地球惑星科学連合2015年大会
  • Place of Presentation: 幕張メッセ（千葉市）
  • Year and Date: 2015-05-28
  • Invited
• [Presentation] 阿蘇火山中央火口丘群における完新世溶岩流の古地磁気学的研究 (2014)
  • Author(s): 望月伸竜，渋谷秀敏，弥頭隆典，宮縁育夫
  • Organizer: 地球電磁気・地球惑星圏学会第136回講演会
  • Place of Presentation: キッセイ文化ホール
  • Year and Date: 2014-11-02
• [Presentation] 中新世後期における野間エクスカーション期間中の古地磁気強度の推定 (2014)
  • Author(s): 岡山和也，望月伸竜，和田穣隆，乙藤洋一郎
  • Organizer: 地球電磁気・地球惑星圏学会第136回講演会
  • Place of Presentation: キッセイ文化ホール
  • Year and Date: 2014-10-31
• [Presentation] 下北半島沖海底コアC9001C に挟在する更新世テフラ群の同定口頭発表 (2014)
  • Author(s): 長谷川健，菅谷真奈美，岡田誠，望月伸竜，藤井哲夢，渋谷秀敏
  • Organizer: 日本地球惑星科学連合2014年大会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2014-05-02
• [Presentation] 溶結凝灰岩による絶対古地磁気強度測定：相対古地磁気強度と絶対古地磁気強度の対比 (2014)
  • Author(s): 藤井哲夢，望月伸竜，長谷川健，岡田誠，渋谷秀敏
  • Organizer: 日本地球惑星科学連合2014年大会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2014-04-30
• [Presentation] 阿蘇火山中央火口丘群における火山岩・テフラの古地磁気学的研究 (2014)
  • Author(s): 阿比留拓哉，渋谷秀敏，望月伸竜，弥頭隆典，宮縁育夫
  • Organizer: 日本地球惑星科学連合2014年大会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2014-04-30
• [Presentation] プナルウエクスカーションにおける絶対古地磁気強度変動の研究
  • Author(s): 望月伸竜，小田啓邦，石塚治，山崎俊嗣
  • Organizer: 地球電磁気・地球惑星圏学会第134回講演会
  • Place of Presentation: 高知大学
• [Presentation] 広域テフラに対比される溶結凝灰岩による絶対古地磁気強度測定: 相対古地磁気強度との対比と絶対値較正
  • Author(s): 藤井哲夢，望月伸竜，長谷川健，岡田誠，渋谷秀敏
  • Organizer: 地球電磁気・地球惑星圏学会第134回講演会
  • Place of Presentation: 高知大学
• [Presentation] 阿蘇火山中央火口丘群における完新世火山噴出物の古地磁気学的研究
  • Author(s): 弥頭隆典，望月伸竜，宮縁育夫，久保田恭平，渋谷秀敏
  • Organizer: 日本地球惑星科学連合2013年大会
  • Place of Presentation: 幕張メッセ
• [Presentation] 溶結凝灰岩の古地磁気強度測定: 屈曲したNRM-TRM1＊プロットについての検討
  • Author(s): 藤井哲夢，望月伸竜，長谷川健，岡田誠，渋谷秀敏
  • Organizer: 日本地球惑星科学連合2013年大会
  • Place of Presentation: 幕張メッセ