スタラグミットのデータから西ヨーロッパにおけるダンズガード・オシュガー気象振動の正確な年代測定
1IPSL/Laboratoire des Sciences du Climat et de l'Environnement, UMR CEA/CNRS 1572 Bat. 709, L'Orme des Merisiers CEA Saclay, 91191 Gif sur Yvette cedex, France. genty@lsce.saclay.cea.fr
Nature
|February 21, 2003
まとめ
Dansgaard-Oeschger現象は,最後の氷河期中に突然の気候変動を引き起こしました. この研究は,正確なスタラグミット年代測定を用いて,フランスにおけるこれらの気候の振動と植物の変化を明らかにしています.
科学分野:
- 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
- ジオクロノロジー (Geochronology) について
- パレオエコロジー (古生態学)
背景:
- Dansgaard-Oeschger現象は,最後の氷河期における千年規模の急激な気候振動である.
- 放射性炭素年代測定の限界を超えた彼らの大陸のサインと正確な年代順はよく理解されていません.
- スタラグミットは,高解像度の古気候再構築の可能性を秘めています.
研究 の 目的:
- フランス南西部のダンズガール・オシュガー事件の大陸表現を調査する.
- これらの出来事の正確な年代順をUシリーズ年代測定を用いて確立する.
- 関連する気候と植生の変化を再構築する.
主な方法:
- フランスの南西からスタラガミットを集めました.
- スタラガミット内の炭素と酸素の同位体を分析した.
- ウランシリーズ (234U/230Th) の方法により,スタラガミットの正確な年代測定を行いました.
主要な成果:
- 8万3千年から3万2千年前の急速な気候の振動を特定し,ダンズガード-オシュガー現象と同期した.
- 酸素同位体データは,他の古気候記録との大きな空間的相関を示しています.
- 炭素同位体のデータは,西ヨーロッパにおける,顕著で急速な植生変化を示しています.
- 61.2年から67.4年前にフランス南西部で長期にわたる寒冷期が記録されています.
結論:
- スタラグミットは,ダンズガード-オシュガー現象の信頼性の高い大陸記録を提供します.
- これらの出来事は,大規模な地域における気候と植生に広範な影響を及ぼした.
- この発見は,氷河期気候動態とその生態学的影響の理解を深める.
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