日本地球惑星科学連合2016年大会

講演情報

インターナショナルセッション(口頭発表)

セッション記号 S (固体地球科学) » S-GC 固体地球化学

[S-GC16] Volatile Cycles in the Deep Earth - from Subduction Zones to the Mantle and Core

2016年5月25日(水) 15:30 〜 17:00 304 (3F)

コンビーナ:*角野 浩史(東京大学大学院総合文化研究科広域科学専攻相関基礎科学系)、羽生 毅(海洋研究開発機構 地球内部物質循環研究分野)、佐野 有司(東京大学大気海洋研究所海洋地球システム研究系)、Jackson Colin(Geophysical Laboratory, Carnegie Institution of Washington)、座長:角野 浩史(東京大学大学院総合文化研究科広域科学専攻相関基礎科学系)、羽生 毅(海洋研究開発機構 地球内部物質循環研究分野)

16:00 〜 16:30

[SGC16-09] Global water cycle constrained by the evolution of dynamic hypsometry

★招待講演

*Jun Korenaga1 (1.Department of Geology and Geophysics, Yale University)

キーワード:oceans, mantle convection, plate tectonics

The presence of liquid water on the surface is one of the important characteristics that make the Earth a unique planet, and it is usually considered to be critical for a planet to be habitable. Also, surface water is often believed to be essential for the operation of plate tectonics, which in turn enables the return of surface water to the planetary interior. The amount of surface water is thus a time-dependent variable that is controlled by the dynamics of Earth's interior. The Earth not only has surface water but also has just a right amount of it to allow the subaerial exposure of continental crust, which is important for the modulation of the atmospheric composition as well as various biogeochemical cycles. To better understand the role of water in the Earth history, therefore, we need to decipher how the distribution of water between the surface and the deep interior has changed with time and how it has affected the surface environment. In this contribution, we focus on reconstructing the history of surface water by assembling relevant observational constraints and theoretical considerations. It is now possible to derive a fairly robust constraint on the history of surface water, at least back to around 3 Ga, by examining the constancy of continental freeboard in light of the evolution of dynamic hypsometry. We also discuss its implications for the coevolution of Earth's interior and surface environment.