在西欧的Dansgaard-Oeschger气候振荡的精确约会从石岩数据
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
概括
丹斯加德-奥斯格尔事件在最后一个冰川时期引起了突然的气候变化. 这项研究揭示了法国的气候振荡和植被变化,使用精确的岩年代.
科学领域:
- 古气候学 古气候学
- 地质时间学 (Geochronology)
- 古生态学 古生态学
背景情况:
- 丹斯加尔德-奥什格尔事件是在最后一个冰川时期发生的千年级的突然气候振荡.
- 它们的大陆特征和精确的时间表,超出放射性碳测年限,并未得到充分理解.
- 斯塔拉格米特为高分辨率的古气候重建提供了潜力.
研究的目的:
- 调查法国西南部丹斯加尔德-奥什格尔事件在非洲大陆的表现.
- 为了确定这些事件的精确时间表,使用U系列约会.
- 为了重建相关的气候和植被变化.
主要方法:
- 从法国西南部收集了一个石石.
- 在斯塔拉格米特中分析了碳和氧同位素.
- 使用系列 (234U/230Th) 方法精确地测定了石的日期.
主要成果:
- 确定了83,000至32,000年前的快速气候振荡,与Dansgaard-Oeschger事件同步.
- 氧同位素数据显示与其他古气候记录有很大的空间连贯性.
- 碳同位素数据表明西欧的植被发生了显著的,快速的变化.
- 记录了法国西南部从61.2到67.4年前的长期寒冷阶段.
结论:
- 斯塔拉格米特提供了一个可靠的大陆记录Dansgaard-Oeschger事件.
- 这些事件对大地区的气候和植被产生了广泛的影响.
- 这些发现提高了对冰川时期气候动态及其生态后果的理解.
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