カリフォルニア州サンタモニカ・シェルフのホロセンの海平面曲線
まとめ
サンタモニカ・シェルフの海水位は1万8000年にわたって大きく変動し,フランドリアン・トランスグレッション (Flandrian transgression) の際に顕著に上昇した. この研究は,複数の年代測定と分析方法を使用して,過去の海面の変化を再構築します.
科学分野:
- * 四次期の地質学
- * パレオシアノグラフィー
- * 海水位に関する研究
背景:
- * 過去の海面変動の理解は,将来の沿岸の変化を予測するために不可欠です.
- * サンタモニカ・シェルフは,四次期の海面上昇の歴史の貴重な記録を提供している.
研究 の 目的:
- *サンタモニカ・シェルフの過去1万8000年の海面曲線を再構築する.
- * フランダース・トランスグレーションにおける海面変化の動態を分析する.
主な方法:
- * 堆積物の放射性炭素年代測定.
- * 堆積物学的データ分析.
- * 高解像度の地震ストラティグラフィック分析により,四季期の後半のテラス堆積物.
主要な成果:
- * 海水位は,約1万8千年前には現在の水位より117メートル下がっていた.
- * フランダース侵攻の間,海面は上昇し,下がり,そして再び上昇し,現在の水準を下回った.
- *海平面の上昇は,よりゆっくりと,現在の位置に絶え間なく続いた.
結論:
- *海平面の曲線は,四次期の後半の複雑な変動を示しています.
- * フランダースの違反は,海平面の非線形な動きを伴う.
- * この研究は,数千年にわたる地域の海面の変化の詳細な記録を提供します.
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