日本地球惑星科学連合2014年大会

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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-IT39_2PO1] 地球深部ダイナミクス:プレート・マントル・核の相互作用

2014年5月2日(金) 14:00 〜 15:15 3階ポスター会場 (3F)

コンビーナ:*綿田 辰吾(東京大学地震研究所海半球観測研究センター)、境 毅(愛媛大学地球深部ダイナミクス研究センター)、中川 貴司(海洋研究開発機構地球内部ダイナミクス領域)

14:00 〜 15:15

[SIT39-P10] 地球核条件下にレーザー衝撃圧縮されたFe-Ni合金の音速

*境家 達弘1横山 直也1細木 亮太1近藤 忠1寺崎 英紀1重森 啓介2弘中 陽一郎2 (1.大阪大学大学院理学研究科宇宙地球科学専攻、2.大阪大学レーザーエネルギー学研究センター)

キーワード:音速, レーザー, 衝撃波, 鉄合金, 地球核, 実験

When we consider the structure of Earth's interior, the sound velocity is one of the important physical properties of the interior materials because it can be directly compared with the seismological data (1) which can yield the physical properties of the Earth's interior. Cosmochemical data and the composition of iron meteorites suggest that Earth's core contains mainly Fe-Ni alloy with 5-25 wt.% Ni. Although Lin et al. (2) and Kantor et al. (3) measured compressional sound velocities of Fe-Ni alloys at room temperature by inelastic x-ray scattering (IXS) at diamond anvil cell (DAC), the sound velocity data of liquid Fe-Ni alloys is very few (4).
We performed laser-shock experiments of liquid Fe-Ni alloys at HIPER system of Gekko-XII laser in Institute of Laser Engineering, Osaka University (5). Sound velocities were measured by side-on radiography (6, 7). We obtained sound velocities of Fe-Ni alloys at pressures up to 770 GPa. The sound velocity of Fe-Ni alloy was about 10% lower than that of liquid Fe at inner core boundary (ICB) pressure.
Part of this work was performed under the joint research project of the Institute of Laser Engineering, Osaka University.

References
1. A.M. Dziewonski, D.L. Anderson, Phys. Earth Planet. Inter. 25, 297 (1981).
2. J.F. Lin et al., Geophys. Res. Lett. 30, 2112 (2003).
3. A.P. Kantor et al., Phys. Earth Planet. Inter. 164, 83 (2007).
4. P.M. Nasch, M.H. Manghnani, Geophys. Monograph Ser. 101, 307 (1998).
5. C. Yamanaka et al., Nucl. Fusion 27, 19 (1987).
6. K. Shigemori et al., Rev. Sci. Instrum. 83, 10E529 (2012).
7. T. Sakaiya et al., Earth Planet. Sci. Lett. in press (2014).