冰河时代的结束 冰河时代的结束
Hai Cheng1, R Lawrence Edwards, Wallace S Broecker
1Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, USA.
Science (New York, N.Y.)
|October 10, 2009
概括
来自中国石岩的亚洲季风降水记录与过去的冰川终结精确相关. 这证实北半球夏季阳光是结束冰河时代的触发因素,影响全球气候和二氧化碳水平.
科学领域:
- 古气候学 古气候学
- 地质化学 地质化学
- 四分学科学 四分学科学
背景情况:
- 了解过去的冰川终结对于预测未来的气候变化至关重要.
- 亚洲季风 (AM) 在全球气候动态中发挥着重要作用.
- 古气候记录的精确相关性对于重建过去的气候事件至关重要.
研究的目的:
- 在过去的冰河时代使用石岩记录来描述亚洲季风降水.
- 准确地将AM记录与其他古气候档案 (冰芯,海洋沉积物) 相关联.
- 调查冰川终结的触发因素和机制.
主要方法:
- 来自中国三宝洞穴的石石的230Th日期.
- 分析氧同位素记录从石岩.
- 斯塔拉格米特数据与冰芯和海洋沉积物记录的相关性.
主要成果:
- 圣宝洞穴的氧同位素记录为过去四个冰川终结提供了详细的AM降水数据.
- 机械制造记录与冰芯和海洋沉积物数据精确相关,确定事件时间.
- 观测证实北半球夏季阳光是冰盖退缩的最初触发因素.
结论:
- 冰川的终结是由北半球夏季阳光照射开始的.
- 融水涌入北大西洋改变了海洋和大气循环,影响了全球气候.
- 增加的二氧化碳和阳光照射推动了冰盖的衰退,海平面和二氧化碳之间可能存在积极的反.
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