Studies on marine environments of Indonesian throughflow and its impact on the climate and coral reefs

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H05329
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: Okayama University
• Principal Investigator: Inoue Mayuri 岡山大学, 自然科学研究科, 准教授 (20451891)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: インドネシア / サンゴ骨格 / 微量元素 / 温暖化 / 酸性化

Outline of Final Research Achievements

Geochemical tracers such as Sr/Ca, U/Ca, oxygen and carbon isotope ratios were measured on annual bands of the coral skeleton collected from Java Sea in order to reconstruct marine environments for the past 70 years. As a result, 0.7 degree C warming was found for this time period. Especially impact from emission of fossil fuels seems to be intensified since 1970s as seen in the record of carbon isotope ratios as well as U/Ca ratios. Based on the variation of Sr/Ca and U/Ca ratios for 70 years, seawater pH would be decreased since 1970s probably due to the anthropogenic CO2 emission.

Free Research Field

地球化学

Academic Significance and Societal Importance of the Research Achievements

現代の海洋観測技術が発展した社会においても、地形の複雑さなどによりインドネシア多島海の海洋環境はよく分かっていない点が多い。今回のサンゴ試料を用いた研究により、ジャワ海においても全球規模と同様の温暖化の影響が見られたこと、さらに人為起源二酸化炭素放出の影響も受けており、海洋酸性化の影響もこれから深刻になってくることが予測されたことは、学術的、社会的にも意義のある発見である。