A millennial scale planktonic foraminifer record of the mid-Pleistocene climate transition from the northern South China Sea
A millennial scale planktonic foraminifer record of the mid-Pleistocene climate transition from the northern South China Sea
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DOI：
10.1016/j.palaeo.2005.04.018
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发表时间：
2005-08
期刊：
影响因子：
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通讯作者：
F. Zheng;Qianyu Li;Baohua Li;Muhong Chen;X. Tu;Jun Tian;Z. Jian
中科院分区：
文献类型：
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作者：
F. Zheng;Qianyu Li;Baohua Li;Muhong Chen;X. Tu;Jun Tian;Z. Jian
南海中国北部∼1144站浮游有孔虫的高分辨率记录(ODP1100年)揭示了中更新世过渡期快速而强烈的气候变化。暖水物种的丰度从海洋同位素阶段(MIS29)的平均60%下降到MIS22的40%，随后冷水物种的丰度随着年龄的增加而稳步增加。在MIS22期间，许多深水、温水物种减少到最低限度，在较年轻的冰川时期仍然极其罕见，甚至消失，这表明该地区的海面正在逐步冷却。估计的SST显示出很大的波动，主要是在冰期-间冰期的过渡时期。横跨MIS23/22边界的最大冬季温差为11°C(17-28°C)，这可能对应于0.9 MYR横跨MPT中心的北部冰盖的主要增长，以及东亚地区冬季风的加强。MPT事件不仅使物种丰度的变化与冰期-间冰期循环之间有了更好的相关性，而且还使温跃层受到更大的限制，在随后的冰期期间明显变浅。氧同位素记录和浅水物种的丰度显示出与41000年和100000年周期密切相关的功率谱。深水生物物种与浮游生物δ18O(一个浅滩温跃层)和更多的冰川δ18O之间的低相关性表明，过去1-0.5MYR期间，南中国海的冬季风增强对表层和地下水域造成了扰动。
A high resolution record (∼1100 yr) of planktonic foraminifers from ODP Site 1144 in the northern South China Sea reveals rapid and strongly variable climatic changes during the mid-Pleistocene transition period. The abundance of warm water species decreased from an average of 60% in marine isotope stage (MIS) 29 to <40% at MIS 22, followed by a steady increase in cool water species toward younger intervals. Many deep dwelling, warm water species decreased to a minimum during MIS 22 and remained extremely rare or even became absent in younger glacial intervals, indicating stepwise sea surface cooling in the region. Estimated SSTs show large fluctuations mostly at glacial–interglacial transitions. A maximum winter temperature difference of 11 °C (17–28 °C) across MIS 23/22 boundary likely corresponded to a major growth of boreal ice sheets across the MPT center at 0.9 myr, coupled with a strengthened winter monsoon over East Asia . The MPT event not only led to a better correlation between changes in species abundances and glacial–interglacial cycles but also a more constrained thermocline that shoaled considerably during subsequent glacial periods. The oxygen isotope record and the abundance of shallow water species display power spectra closely in pace with the 41,000 and 100,000 years cyclicities. A lower coherence over these cyclicities between deep-water dwelling species and the planktonic δ18O, a shoaled thermocline, and more pisitive glacial δ18O together suggest disturbances of surface and subsurface waters by intensified winter monsoons over the last 1.1–0.5 myr in the South China Sea.