固体コンベクションの地質学的証拠は,ヨーロッパの氷の殻の固体コンベクションにある

R T Pappalardo¹, J W Head, R Greeley

¹Department of Geological Sciences, Brown University, Providence, Rhode Island 02912-1846, USA. robert_pappalardo@brown.edu

Nature

|February 5, 1998

まとめ

ヨーロッパはヨーロッパです.

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:

木星の衛星であるヨーロッパは,地質学的に活発で氷が豊富な表面を持っています.
潮力による内部熱は,地下液体の水層を維持する可能性があります.
熱の損失と再表面化のメカニズムは不明である.

研究の目的:

ヨーロッパの表面を形作る地質学的プロセスを調査する.
ガリレオ宇宙船によって観測された地表の特徴を解釈する.
地下液体の水の海が存在する証拠を評価する.

主な方法:

高解像度のガリレオ宇宙船のヨーロッパ画像の分析.
表面の特徴 (穴,ドーム,スポット) の形態学的および地質学的解釈.
熱誘導による固体コンベクションのモデリング. ヨーロッパの氷の殻内.

主要な成果:

ダイアピル (上昇する暖かい氷の質量) として解釈された明確な表面特徴を特定しました.
これらの特徴の形成は,氷殻の固体コンベクションによって説明される.
結果は,地表下にある液体の水層や海洋の可能性と一致しています.

結論:

固体コンベクションによって引き起こされるダイアピル上流は,ヨーロッパで再表面化の合理的なメカニズムです.
この発見は,地下液体の水の海という仮説を裏付けている.
ヨーロッパの海洋の決定的な証拠を得るには,さらなる観測が必要である.

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