日本地球惑星科学連合2018年大会

講演情報

[EE] Evening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-IT22] 核-マントルの相互作用と共進化

2018年5月22日(火) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:飯塚 毅(東京大学)、渋谷 秀敏(熊本大学大学院先端科学研究部基礎科学部門地球環境科学分野)、土屋 卓久(愛媛大学地球深部ダイナミクス研究センター、共同)、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)

[SIT22-P04] High pressure generation up to 24 gigapascals using a D-DIA apparatus combined with jacketed anvils

*大内 智博1 (1.愛媛大学地球深部ダイナミクス研究センター)

キーワード:D-DIA、焼き嵌めアンビル、X線透過型アンビル

Rheological properties of high-pressure polymorphs of olivine are important to understand the cause of seismic anisotropy, viscosity structure, deep-focus earthquakes in the deeper part of the Earth’s mantle. Three types of deformation apparatus, namely, the D-DIA type (Wang et al., 2003), the rotational Drickamer apparatus (RDA: Yamazaki and Karato, 2001), and the Kawai-type apparatus for triaxial deformation (KATD: Nishihara, 2008) have been developed to deform high-pressure polymorphs of olivine. Although recent studies by Girard et al. (2015) and Tsujino et al. (2016) succeeded to deform bridgmanite at lower mantle pressures and temperatures using a RDA and a KATD respectively, in-situ D-DIA experiments are still limited to the conditions of lower part of the mantle transition zone (Kawazoe et al., 2016). The main cause disturbing further pressure generation using an in-situ D-DIA apparatus is relatively low toughness of the x-ray transparent anvils made from sintered diamond or cubic BN. In the geometry of cubic-type multianvil apparatus, the available press load needs to be low (usually < 0.6 MN) to avoid the breakage of the x-ray transparent anvils. The advantages of D-DIA apparatus are as follows: i) compatible with acoustic emission monitoring (i.e., many transducers are available) and ii) temperature can be monitored by using a thermocouple. To explore the quantitative deformation experiments at lower mantle conditions, we adopted the ‘jacketed’ 6-6 type anvils (Yamada et al., 2016) and optimized the cell assembly using preformed gaskets (e.g., Kawazoe et al., 2010). Combining these techniques, I succeeded to generate 24 GPa at room temperatures using a D-DIA apparatus (in the case of truncation edge length = 3 mm). Pressures higher than 20 GPa are also available using the ‘jacketed’ x-ray transparent anvils. Optimization of the design of ‘jacketed’ x-ray transparent anvil and cell assembly would lead to quantitative deformation experiments at lower mantle conditions in near future.