イリノイの氷河期における海平面の低下:バハマの"青い穴"からの証拠
まとめ
バハマ諸島で海面下45メートルで見つかった化石スタラグミットは,16万~13万9000年前のイリノイの氷河期に海面が少なくとも42メートル低下したことを示している.
科学分野:
- 地質学 地質学 地質学
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- スペレオロジー (洞窟学)
背景:
- 水中のカルスト洞窟システムは,過去の環境状態に関するユニークな洞察を提供します.
- スタラグミットは地質学と気候の歴史の記録を保存することができます.
研究 の 目的:
- 沈没した洞窟物を使って過去の海面を測定する.
- イリノイの氷河期における海面の変化を再現するために.
主な方法:
- バハマのアンドロス島近くの水中の洞窟からスタラグミットを回収.
- スペレオテムのウラン・シリーズ年代測定.
- 海洋の炭酸塩汚染を修正する.
主要な成果:
- スタラグミットは,現在の海面下45メートルで発見された.
- スペレオテムの堆積は,現在より16万~13万9千年前頃に発生した.
- これは,沈没を考慮して最低42メートルの海面低下を示しています.
結論:
- イリノイの氷河期に海水位はかなり下がっていた.
- 沈没した洞窟は,古海洋学的な再構築のための貴重なアーカイブです.
- この発見は,バハマの氷河期間の海面変動の直接的な証拠を提供します.
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