日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 S (固体地球科学) » S-IT 地球内部科学・地球惑星テクトニクス

[S-IT21] 核-マントルの相互作用と共進化

2019年5月27日(月) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:河合 研志(東京大学大学院理学系研究科地球惑星科学専攻)、飯塚 毅(東京大学)、太田 健二(東京工業大学大学院理工学研究科地球惑星科学専攻)、土屋 卓久(愛媛大学地球深部ダイナミクス研究センター)

[SIT21-P18] First-principles prediction of hydrogen partitioning between the core and mantle

*大場 篤朗1土屋 卓久1 (1.愛媛大学 地球深部ダイナミクス研究センター)

Some recent studies have reported high-P,T hydrous minerals which are stable at the core mantle boundary (CMB) pressure (Sano et al., 2008; Ohhira et al., 2016; Nishi et al., 2017). In order to elucidate the water circulation in the Earth's interior, experiments on the reaction between iron and hydrous minerals or water were also conducted (Iizuka-Oku et al., 2016; Mao et al., 2018; Clesi et al., 2018). However, the partition of hydrogen reported is different in different studies. In this study, we try estimating hydrogen partitioning between molten silicate and liquid iron under the CMB conditions based on the first principles calculation method combined with thermodynamic integration similar to our previous study (Xiong et al., 2018). Here, we assume following the exchange reaction of water between liquid iron and molten silicate is expressed as follows
(16MgSiO3+H2O) + 50Fe ⇔ 16MgSiO3 + (50Fe+H2O)
as a first example with ensuring the charge neutrality. Here, reaction free energy is calculated by the thermodynamic integration molecular dynamics method (Taniuchi & Tsuchiya, 2018). In the moment, simulations suggest that water prefer liquid iron. Now, additional computations are ongoing for improving numerical accuracy. The mechanism dissolving water into liquid iron is also investigated.