火星の北極の堆積物:層図,年齢,地動力学的反応
Roger J Phillips1, Maria T Zuber, Suzanne E Smrekar
1Southwest Research Institute, Boulder, CO 80302, USA. roger@boulder.swri.edu
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.
- 地質物理学 地質物理学とは地質物理学です.
- レーダー・リモートセンシング
背景:
- 火星の北極の層状の堆積物は,惑星の気候の歴史に関する重要な手がかりを保持しています.
- 地下構造を理解することは,過去の環境条件を解読する鍵です.
研究 の 目的:
- レーダーデータを用いて,火星の北極の層状の堆積物の内部層図を調査する.
- 火星の地質学的過程と石層の性質を推論する.
主な方法:
- 火星偵察軌道探査機 (Mars Reconnaissance Orbiter) に搭載された浅層レーダー (SHARAD) 装置からのデータを活用する.
- レーダー反射を分析して,堆積物内の層や構造的特徴を特定します.
主要な成果:
- SHARADは,氷に富んだ地域によって分離された,異なる反射器のパケットで構成された横断的に連続した層を明らかにしました.
- 観測された層図は,数百万年の時間スケールにおける軌道変動 (斜率または偏心) と関連した堆積サイクルを示唆しています.
- 基板の傾斜の分析は,石層の厚さが300kmを超えるか,または一時的なレオロギー状態を示す.
結論:
- 層層の堆積物は,火星の長期的な気候サイクルを記録しています.
- 推論された石層の厚さと潜在的マントルの粘度が,火星の特定の熱進化モデルを指している.
- 火星は,熱を生成する元素のサブコンドリティックな豊富さを持っている可能性が高い.
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