ダイアピールによる土星の月エンケラドスの方向転換
Francis Nimmo1, Robert T Pappalardo
1Department of Earth Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA.
Nature
|June 2, 2006
まとめ
土星の衛星エンケラドスの下にある低密度のダイアピールは,その活発な南極地域を説明するかもしれない. この尿布は,月の自転を方向転換し,構造的ストレスとユニークな熱シグネチャーを引き起こした可能性があります.
科学分野:
- 惑星科学は惑星科学である.
- 地質物理学 地質物理学とは地質物理学です.
- 天体生物学 アストロバイオロジー
背景:
- 土星の氷の月であるエンケラドスは,若い,変形した地形と高い熱流量を持つ南極地域を示しています.
- この熱は,潮散熱によるもので,潜在的にダイアピリスム (低密度の物質の浮出) を引き起こしている可能性が高い.
研究 の 目的:
- エンケラドスの南極ホットスポットと観測された表面変形を説明する低密度のダイアピルの役割を調査する.
- エンケラドスの氷殻とシリケート核の物理的性質を制限するために.
主な方法:
- 低密度のダイアピールによる衛星の方向転換の影響をモデル化.
- 回転変化によって生み出される構造的ストレスパターンを分析する.
- 衝突クレーターの分布や重力の異常など,観測可能な地質学的なサインを予測する.
主要な成果:
- 低密度のダイアピルは,エンケラドスの回転軸の方向転換を引き起こすことによって,極のホットスポットを説明することができます.
- 尿布が氷の殻の中にあった場合,その殻は厚さ (>0.5 kmの弾性厚さ) がある必要があります.
- ディアピルがコアにある場合,方向転換のために必要なコアと氷のカップリングのため,地球規模の地下海はありそうにない.
結論:
- ダイアピリズムによる衛星の方向転換は,エンケラドスの南極変形と一致する構造的ストレスを生成します.
- 衝突クレーターの分布には,典型的な前半球と後半球の非対称性が欠けることがあります.
- 負の重力異常は,低密度のダイアピールの潜在的に観測可能な結果です.
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