日本地球惑星科学連合2021年大会

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[E] 口頭発表

セッション記号 U (ユニオン) » ユニオン

[U-13] Advanced understanding of Quaternary and Anthropocene hydroclimate changes in East Asia:

2021年6月5日(土) 09:00 〜 10:30 Ch.01 (Zoom会場01)

コンビーナ:Li Lo(Department of Geosciences, National Taiwan University)、窪田 薫(神戸大学大学院人間発達環境学研究科)、Chuan-Chou Shen(National Taiwan University)、横山 祐典(東京大学 大気海洋研究所 高解像度環境解析研究センター)、座長:Li Lo(Department of Geosciences, National Taiwan University)、窪田 薫(神戸大学大学院人間発達環境学研究科)、横山 祐典(東京大学 大気海洋研究所 高解像度環境解析研究センター)、Chuan-Chou Shen(National Taiwan University)

09:15 〜 09:30

[U13-02] Increased soil erosion since Southeast Asia economic boom recorded in Porites corals

★Invited Papers

*Xiaohua Li1、Zhen Zeng2、Yi Liu3、Ching-Chih Chang4、Hong-Wei Chiang4、Xuan-Ce Wang5、Weidong Sun1、Hui-Min Yu2、Fang Huang2、Chung-Che Wu4、Tsai-Luen Yu4、Chun-Yuan Huang4、Chuan-Chou Shen4 (1.Institute of Oceanology, Chinese Academy of Sciences、2.University of Science and Technology of China、3.Tianjin University、4.National Taiwan University、5.Yunnan University)

キーワード:soil erosion, Porites coral, Ba/Ca, δ137/134Ba, Southeast Asia, economic boom

Soil erosion has raised public concern in Southeast Asia which has been poorly documented due to the lack of long, continuous records. Here we present two Porites coral records of monthly-resolved Ba/Ca ratios and monthly and yearly-resolved δ137/134Ba from the Nanwan (NW), southern Taiwan, and Son Tra Island (STI), central Vietnam, to explore the extent of soil erosion. Our major finding is that erosion and sediment transport have increase substantially since the regional economic boom and resulted in Ba/Ca ratios significantly elevated during 1987-1996 and 1992-2001 for NW and STI corals, respectively, principally due to increasing pressure on land use. Due to terrestrial inputs yield a homogeneous Ba isotope composition, the δ137/134Ba values of coral NW and STI show essentially constant with the mean isotope fractionation between coral and seawater Δ137/134Bacoral - seawater is -0.1‰, suggesting that Porties coral could be used to trace the Ba isotope composition in ambient seawater. Coupled Ba/Ca and Ba isotopes analysis on Porites coral has the potentially to provide new information about the historical soil erosion events.