深海温度和冰体积的变化跨越了普略纪-普纪的气候转变
Sindia Sosdian1, Yair Rosenthal
1Institute of Marine and Coastal Science and Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ 08901, USA. sindia.sosdian@anu.edu.au
概括
深海温度极大地影响了地球的气候转变,包括北半球冰盖的形成. 这些温度变化解释了普略纪晚期和普略纪中期全球氧同位素记录的很大一部分.
科学领域:
- 古气候学 古气候学
- 海洋学 海洋学 海洋学
- 地质地质地质地质地质地
背景情况:
- 地球的气候系统自纪晚期以来经历了重大变化.
- 北半球冰盖的发展和加剧是这一时期的关键特征.
- 基菌氧同位素 (delta18Ob) 是这些气候变化的主要指标.
研究的目的:
- 在关键气候转变期间重建深海温度变化.
- 为了确定温度变化对全球delta18Ob信号的贡献.
- 为了研究北半球冰盖动态的驱动因素.
主要方法:
- 来自北大西洋的/ (Mg/Ca) 比率的基基基基 (Mg/Ca) 的分析.
- 一个轨道解析的深海温度记录的生成.
- 温度数据与谷菌氧同位素 (delta18Ob) 记录的比较.
主要成果:
- 深海温度变化构成了全球delta18Ob信号的重要组成部分.
- 确定了两个显著的冷却事件:普略纪晚期的过渡 (LPT,2.5-3万年) 和普略纪中期的过渡 (MPT,1.2-0.85万年).
- 较长时间的冰块体积增加与全球冷却有关,而MPT转移到10万年周期表明冰盖动态发生了变化.
结论:
- 深海温度是了解普略纪晚期和普略纪中期气候变化的关键因素.
- MPT的周期性转移表明全球冷却和冰盖行为之间的复杂相互作用.
- Mg/Ca古热度计为过去的气候变化和冰盖演变提供了宝贵的见解.
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