熱伝導性のマントル値と,フォノンの寿命から得られる地熱
1Department of Earth and Planetary Science, Washington University, St. Louis, MO 63130, USA.
Science (New York, N.Y.)
|March 12, 1999
まとめ
この研究では,シリケートとMgOの熱伝導性モデルを提示し,実験データを正確に予測しています. このモデルは,圧力と温度が熱的性質にどのように影響し,石層とマントルの地熱に影響を及ぼすか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.
- 固体物理 固体物理学
- マテリアルサイエンス 材料科学
背景:
- 熱伝導性の正確なモデリングは,地球の熱構造を理解するために不可欠です.
- 以前のモデルは,熱伝送特性の圧力および温度依存性を捉えるのに苦労していました.
研究 の 目的:
- シリケートとMgOの熱伝導性の包括的なモデルを開発し,検証する.
- 格子と放射性熱伝導性の圧力および温度依存性を解明する.
- リトスフィアの地熱とマントルの地熱への影響を調査する.
主な方法:
- モデルの開発のためにフォノン寿命を取得するために赤外線反射性を利用しました.
- 組み込みのグルーナイゼンパラメータ,散量モジュール,および熱膨張性は,輸送特性の依存性を記述します.
- 格子 (kappalat) と放射性 (kapparad) の熱伝導性貢献のための別々の配列を開発しました.
主要な成果:
- このモデルは,環境条件下での実験的な熱伝導度データを成功裏に複製しています.
- 材料特有のパラメータ (a = 0.33 for silicates, 0.9 for MgO) を使用して,カッパラットの温度と圧力の依存関係について正確な関係を確立しました.
- Fe2+の存在下における圧力独立の放射性貢献 (kapparad) を定量化した.
結論:
- 開発されたモデルは,関連する地質学的材料の熱伝導性を予測するための堅固な枠組みを提供します.
- モデルの予測は,急な石層地熱を示唆しています.
- マントルの地熱は,低速帯の無水状態では熱く,水分状態では冷たく予測されています.
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