The Cause of Carbon Isotope Minimum Events on Glacial Terminations
The Cause of Carbon Isotope Minimum Events on Glacial Terminations
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DOI：
10.1126/science.1069401
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发表时间：
2002-04
期刊：
影响因子：
56.9
通讯作者：
H. Spero;D. Lea
中科院分区：
文献类型：
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作者：
H. Spero;D. Lea
冰川终止开始时碳同位素最小值的出现是印度太平洋、亚南极和南大西洋浮游有孔虫碳同位素记录的一个共同特征。我们利用温跃层有孔虫 Neogloboquadrina dutertrei 的 δ13C 记录和赤道东太平洋的表面温度估计来证明 δ13C 最小值事件的发生和南大洋变暖的开始同时发生。海洋记录与南极大气记录中 δ13C 最小值之间的时间一致性表明，冰消事件是对地表水层结破裂、新的环极深水上升流以及低 δ13C 水平流至亚南极锋辐合带的响应。根据地表记录中绝对 δ13C 最小值与南大西洋深处 δ13C 从低到高的转变之间的年龄一致性，我们认为标志着碳同位素最小值结束的 δ13C 上升是由于南大洋北大西洋深水影响的恢复。
The occurrence of carbon isotope minima at the beginning of glacial terminations is a common feature of planktic foraminifera carbon isotopic records from the Indo-Pacific, sub-Antarctic, and South Atlantic. We use the δ13C record of a thermocline-dwelling foraminifera, Neogloboquadrina dutertrei, and surface temperature estimates from the eastern equatorial Pacific to demonstrate that the onset of δ13C minimum events and the initiation of Southern Ocean warming occurred simultaneously. Timing agreement between the marine record and the δ13C minimum in an Antarctic atmospheric record suggests that the deglacial events were a response to the breakdown of surface water stratification, renewed Circumpolar Deep Water upwelling, and advection of low δ13C waters to the convergence zone at the sub-Antarctic front. On the basis of age agreement between the absolute δ13C minimum in surface records and the shift from low to high δ13C in the deep South Atlantic, we suggest that the δ13C rise that marks the end of the carbon isotope minima was due to the resumption of North Atlantic Deep Water influence in the Southern Ocean.