惑星の核条件における固体鉄の熱伝導性の直接測定
Zuzana Konôpková1, R Stewart McWilliams2, Natalia Gómez-Pérez2,3
1DESY Photon Science, Notkestrasse 85, DE-22607 Hamburg, Germany.
Nature
|June 3, 2016
まとめ
新しい測定は地球を明らかにする
科学分野:
- 地理学
- 惑星科学
- 材料科学
背景:
- 地球の核の熱伝導性は 惑星の進化と磁場生成に不可欠です
- 高い熱伝導性の予測は 地質学的モデルと古磁気証拠と矛盾しています
- コア熱伝送の理解における不一致を解決するために,直接的な測定が必要である.
研究 の 目的:
- 鉄の熱伝導性を極度の圧力や温度下で直接測定する.
- 陸上の惑星の核に関する正確なデータを 提供するためです
- 地球の中核の熱輸送の 矛盾するモデルを調和させるため
主な方法:
- ダイナミックにレーザーで加熱された ダイヤモンド・アンビル・セルを使いました
- 水星から地球サイズの 惑星の核に存在する 圧力と温度をシミュレートしたものです
- 固体鉄の熱伝導性を直接測定した.
主要な成果:
- 地球の核の熱伝導性が18~44W/m·Kで測定され,以前の推定値の底辺に近い.
- 結果は古磁気データと合致し 古い地磁石を示唆している
- 発見は古代の固体内核が ジオダイナモと同時代であった可能性を支持している.
結論:
- 測定された熱伝導性は,ジオダイナモモデルのためのより正確な制約を提供します.
- この研究は,初期の歴史から地球のジオダイナモの持続性を支持しています.
- このデータは,固体の中核の年齢と熱的進化の理解を修正します.
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