火星の残った極地層の北南地質の違い
P C Thomas1, M C Malin, K S Edgett
1Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14853, USA. thomas@cuspif.tn.cornell.edu
Nature
|March 21, 2000
まとめ
火星 火星 火星 火星
科学分野:
- 惑星科学は惑星科学である.
- 地質学 地質学 地質学
- 気候学 気候学
背景:
- 極地プロセスは,地球規模の気候変動の敏感な指標である.
- 火星の極域には,層状の堆積物や季節性/残留CO2の凍土など,独特の地質・気候の特徴がある.
- 残留の氷冠の正確な性質と,層状の堆積物との関連は不明である.
研究 の 目的:
- 火星の極の残留氷冠の地質学的性質を調査するために.
- 南極と北極の残層を比較し,それと底辺の鉱床との関係を比較する.
- 極地表層の形態学に基づいて,火星の長期的な気候非対称性を評価する.
主な方法:
- 高解像度軌道データの分析により,極地残層の地形と形状を調査する.
- 南極残層の特徴と北極残層の特徴の比較.
- 観測された特徴の地質学的解釈は,氷の覆いと実質的な地質学的単位を区別するために行われます.
主要な成果:
- 南極の残層は,重要な崩壊と侵食の特徴を持つ独特の地質学的な単位です.
- 北極の残留キャップは,その下にある層状の材料にスムーズに移行します.
- 両極の残層の間には,短命の氷の変異ではなく,実質的な違いが存在します.
結論:
- 南極の残層は,単純な氷の層とは異なり,実質的な地質学的特徴を表しています.
- 北極と南極の残層の異なる形状は,火星の長期的な気候アシンメトリーをサポートしています.
- これらの発見は,火星の気候の進化に関する重要な洞察を提供します.
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