レイチェル湖噴火の正確な日付は,若いドライアスと同期しています
Frederick Reinig1, Lukas Wacker2, Olaf Jöris3,4,5
1Department of Geography, Johannes Gutenberg University, Mainz, Germany. reinig@geo.uni-mainz.de.
Nature
|July 1, 2021
まとめ
Laacher See噴火 (LSE) は,以前考えられていたよりも1世紀以上前に発生し,紀元前13,006年±9年である. この改訂されたタイミングは,ヤング・ドライアスの始まりを, BPの12,807 ± 12年にシフトさせます.
科学分野:
- 火山学
- 古代気候学
- 地質年代学
背景:
- ラッシャー湖噴火 (Laacher See eruption,LSE) は,ヨーロッパにおけるプレイストセンの上期の大火事である.
- LSEのテフラ堆積物は,古気候アーカイブを同期するために不可欠ですが,その正確な年齢は不明でした.
- LSEの年齢に関する以前の推定は精度が不足し,気候イベントの年代順に影響を与えていました.
研究 の 目的:
- デンドロクロノロジックと放射性炭素の方法を用いて,ラッチャーシー噴火の年齢を正確に決定する.
- LSEと関連してヤング・ドライアスの発生時期を再評価する.
- LSE,北大西洋の気候,そして海洋循環の関係を調査する.
主な方法:
- LSEのピロクラスティック堆積物によって埋もれた亜化石の木のデンドロクロノロジカル分析.
- これらの亜化石の木の放射性炭素年代測定です
- 改訂されたLSE年代順の比較と欧州の氷河記録とグリーンランドの氷芯データ.
主要な成果:
- LSEは13006年 ± 9年 BPに日付付けられており,以前から認められていたより1世紀以上早くです.
- ユング・ドライアスの始まりは,紀元前12,807年±12年と改定されています.
- 改訂された年代順は,北大西洋-欧州のセクター全体で若いドライアスの始まりを同期します.
結論:
- LSEはヤング・ドライアス冷却 (グリーンランド・スタディアル-1) を直接引き起こすことはなかった.
- 温暖化条件下で弱体化した大西洋南側転覆循環という共通のメカニズムは,両方のイベントに影響を与えました.
- この研究は,後期氷河期から初期ホロセンの移行について,より堅固な年代的枠組みを提供します.
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