台湾のオロゲンにおける侵食,流出変動,地震性との関連
Simon J Dadson1, Niels Hovius, Hongey Chen
1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK. simon00@esc.cam.ac.uk
Nature
|December 12, 2003
まとめ
台湾の山の浸食は,構造的変形,嵐,および基底の弱さによって引き起こされ,すべての時間尺度で高くなります. 侵食パターンは,変化する構造的活動に伴い,時間とともに変化します.
科学分野:
- 地球科学 地球科学 地球科学
- 地質学 地質学 地質学
- ジオモルフォロジー ジオモルフォロジー
背景:
- 山岳帯の侵食が地形を形成し,海に沈殿物を運ぶ.
- 侵食を理解するには,現在のレリーフと降水だけでなく,複数の時間スケールの測定が必要です.
- 台湾のアクティブ・テクトニクスは,侵食を研究するためのユニークな自然実験室を提供します.
研究 の 目的:
- 台湾の山脈における様々な時間スケールにおける侵食率を定量化するために.
- 構造的変形,気候,侵食の関係を調査する.
- 侵食パターンが地質学的条件の変化とともにどのように進化するかを理解する.
主な方法:
- 現代の河川の堆積物負荷を用いて侵食率を推定する.
- ホロセンの川の切断を分析する.
- 熱クロノメトリーを用いて,長期 (百万年) の侵食の歴史を復元する.
主要な成果:
- すべての研究された時間スケールで高い侵食率 (3-6 mm/年) が観察されました.
- 侵食パターンは時間とともに動的に変化し,移動する構造的変形に結びついています.
- 近代的な侵食は,地震性や嵐による流出と相関しており,急速な変形,頻繁な嵐,弱い基底の地域で最も高い割合を示しています.
結論:
- 台湾の山々は,一貫して高い侵食率を経験しています.
- 侵食は,構造学,気候,岩石学の相互作用によって影響を受けるダイナミックなプロセスです.
- 局所的な構造的変形は,地形的な地形が低い地域でも,高い侵食の主要な要因です.
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