Development of new reliable environmental proxies for reconstructing bottom-water conditions

• Project/Area Number: 24651017
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: Ibaraki National College of Technology
• Principal Investigator: ISHIMURA Toyoho 茨城工業高等専門学校, 物質工学科, 准教授 (80422012)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2012: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 安定同位体比 / 底層水 / 有孔虫 / 微量分析 / 環境指標 / 生物源炭酸塩 / 古環境解析 / 海洋環境 / 地球化学 / 炭酸塩 / 安定同位体 / 古環境 / 炭酸カルシウム / 酸素同位体

Research Abstract

We analyzed the isotopic composition of individual benthic foraminifera of multiple species by using a customized high-precision analytical system, and found that the magnitude of the isotopic disequilibrium between benthic foraminiferal shell and the surrounding bottom seawater in different species is correlated with inter-individual isotopic variations. As a result, we can choose suitable species as bottom-water proxies by using the inter-individual isotopic variations. Our findings will allow the use of isotope data for benthic foraminifera as more reliable proxies for reconstructing past bottom-water conditions.

Research Products

• [Journal Article] Variation in stable carbon and oxygen isotopes of individual benthic foraminifera: tracers for quantifying the magnitude of isotopic disequilibrium. (2012)
  • Author(s): Ishimura, T., Tsunogai, U., Hasegawa, S., Nakagawa, F., Oi, T., Kitazato, H., Suga, H., Toyofuku, T.
  • Journal Title: Biogeosciences Volume: 9 Issue: 11 Pages: 4353-4367
  • DOI: 10.5194/bg-9-4353-2012
  • Peer Reviewed
• [Presentation] 底生有孔虫Uvigerina属の炭素酸素安定同位体組成の環境指標としての有用性の再検討～種間おいび個体間の同位体組成比較から～ (2013)
  • Author(s): 田中崇史・石村豊穂・木元克典・原田尚美・鈴木淳
  • Organizer: 日本地球化学会年会
  • Place of Presentation: 筑波大学
• [Presentation] 底生有孔虫の炭素酸素安定同位体組成・"vital effect"の全体像を捉える~環境指標としての高精度化とその有効活用をめざして~ (2013)
  • Author(s): 石村豊穂・角皆潤・長谷川四郎・中川書千・大井剛志・北里洋・菅寿美・豊福高志
  • Organizer: 日本地球化学会年会
  • Place of Presentation: 筑波大学
• [Presentation] 底生有孔虫 Uvigerina属の炭素酸素安定同位体組成の環境指標としての有用性の再検討 ―種間および個体間の同位体組成比較からー (2013)
  • Author(s): 田中 崇史・石村 豊穂・木元 克典・原田 尚美・鈴木 淳
  • Organizer: 日本地球化学会
  • Place of Presentation: 筑波大学
• [Presentation] 底生有孔虫の炭素酸素安定同位体組成・”vital effect”の全体像を 捉える ~環境指標としての高精度化とその有効活用をめざして~ (2013)
  • Author(s): 石村豊穂・角皆潤・長谷川四郎・中川書子・大井剛志・北里洋・菅寿美・豊福高志
  • Organizer: 日本地球化学会
  • Place of Presentation: 筑波大学
• [Presentation] 高pCO2 海水に曝された大型底生有孔虫の炭酸塩殻の炭素同位体比記録 (2013)
  • Author(s): 氷上愛・石村豊穂・藤田和彦・鈴木淳・野尻幸宏・酒井一彦・川幡穂高
  • Organizer: 日本地球化学会
  • Place of Presentation: 筑波大学