Borneo peat coring; reconstruction of tropical atmospheric convection activity during the llast 4000 years

• Project/Area Number: 15H05210
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Geology
• Research Institution: Hokkaido University
• Principal Investigator: YAMAMOTO Masanobu 北海道大学, 地球環境科学研究院, 准教授 (60332475)
• Co-Investigator(Kenkyū-buntansha): 関 宰 北海道大学, 低温科学研究所, 准教授 (30374648) ; 林 竜馬 滋賀県立琵琶湖博物館, 研究部, 学芸員 (60636067)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥16,250,000 (Direct Cost: ¥12,500,000、Indirect Cost: ¥3,750,000); Fiscal Year 2017: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2016: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000); Fiscal Year 2015: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
• Keywords: ボルネオ / 完新世 / 泥炭 / 乾湿変動 / エルニーニョ / 微粒炭 / 野火 / 太陽放射量 / 古気候 / セルロース酸素同位体 / 地質学 / 第四紀学 / 酸素同位体 / セルロース / 熱帯

Outline of Final Research Achievements

We generated a 6000-year long charcoal record from three different sites in northwestern Borneo that shows large fluctuation in charcoal abundance. Two different sites at 460 km distance show common abundance peaks, suggesting that climate change regulated wild fire frequency. The abundance peak appeared every several hundred years, showing a 560-year periodicity. The peaks correspond well to those of solar irradiance and the frequency of El Nino-induced flooding in an Ecuadorian lake from 4000 to 1000 year BP, but the correspondence is not significant and even reverse in other periods. There is no clear correspondence with the East Asian summer and winter monsoon records. We suggest that multi-centennial scale changes in the frequency of El Nino was a factor controlling precipitation in northwestern Borneo and the frequency of wildfires in the peatlands.

Research Products

• [Int'l Joint Research] サラワク熱帯泥炭研究所/マレーシアトレンガヌ大学/マレーシア地質鉱物局(マレーシア)
• [Int'l Joint Research] サラワク熱帯泥炭研究所/マレーシアトレンガヌ大学/マレーシア鉱物地質局(マレーシア)
• [Journal Article] ボルネオでの泥炭コアリング (2017)
  • Author(s): 山本正伸
  • Journal Title: PALEO Volume: 5 Pages: 1-13
  • Open Access
• [Presentation] ボルネオ島泥炭分析による過去4000 年間の古環境 復元 (2018)
  • Author(s): 菊池隼史・山本正伸・関宰・林竜馬・アブドラ・スライマン・ハスリザ ル・ビン・シャリ・ルリー・メリング
  • Organizer: 第２回地球環境史学会年会
• [Presentation] Cellulose oxygen isotopes of peat as a tool of paleoclimate reconstruction (2018)
  • Author(s): Yamamoto, M., Seki, O., Kikuchi, T., Hayashi, R., Abdullah Sulaiman, A., Shaari, H., Melling, L.
  • Organizer: 15th International Peat Congress
  • Int'l Joint Research
• [Presentation] ボルネオ泥炭中微粒炭量からみた過去6000年間の西部熱帯太平洋乾湿変動 (2017)
  • Author(s): 山本 正伸、菊池 隼史、櫻井 弘道、林 竜馬、関 宰、大森 貴之、アブドラ スライマン、ハスリザル ビンシャリ、ルリー メリング
  • Organizer: 地球惑星科学連合2017年大会
• [Presentation] Multi-centennial variability of western tropical Pacific hydrology during the last 6000 years based on charcoal records from Borneo (2017)
  • Author(s): Yamamoto, M., Kikuchi, T., Sakurai, H., Hayashi, R., Seki, O., Omori, T., Sulaiman, A., Shaari, H., Melling, L.
  • Organizer: IODP-PAGES Workshop on Global Monsoon in Long-term Records
  • Int'l Joint Research