地球の内核の弾性アニソトロピー
Anatoly B Belonoshko1, Natalia V Skorodumova, Anders Rosengren
1Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, SE-100 44 Stockholm, Sweden. anatoly.belonoshko@fysik.uu.se
Science (New York, N.Y.)
|February 9, 2008
まとめ
地球の内核は地震的アニソトロピーを示し,音波はスピン軸に沿ってより速く移動する. 分子ダイナミクスシミュレーションでは,六角形の鉄ではなく,体中心の立方体鉄が,このアニソトロピーを説明することを明らかにしています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- マテリアルサイエンス 材料科学
- 地震学 地震学とは
背景:
- 地球の固体内核は,弾性的にアニソトロプである.
- 地震波は,赤道平面よりもスピン軸に沿ってより速く移動します.
- 六角形の鉄結晶を含む以前の説明は,温度に依存する同otropyのため,可能性は低いです.
研究 の 目的:
- 地球の内核における地震性アニソトロピーの原因を調査する.
- 内核アニソトロピーの体中心立方鉄の役割を評価する.
主な方法:
- 分子力学シミュレーション. 分子力学シミュレーション.
- 地震波の伝播のシミュレーション.
- 内核条件における鉄の弾性特性の分析.
主要な成果:
- 体中心の立方体鉄は,高い対称性にもかかわらず,音波に対して高度にアニソトロプ的である.
- シミュレーションでは,体中心の立方体鉄の12%のアニソトロピーを示しています.
- この値は,観測された内核アニソトロピーを説明するのに十分です.
結論:
- 身体中心の立方体鉄は,地球の内核の地震性アニソトロピーの原因である可能性が高い.
- 体中心の立方鉄の高い対称性は,有意な弾性アニソトロピーを排除しない.
- この発見は,内核の性質に関する実験データとシミュレーションデータを一致させています.
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