Intensified mid-Holocene Asian monsoon recorded in corals from Kikai Island, subtropical northwestern Pacific
Intensified mid-Holocene Asian monsoon recorded in corals from Kikai Island, subtropical northwestern Pacific
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DOI：
10.1016/j.yqres.2006.12.005
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发表时间：
2007-03
影响因子：
2.3
通讯作者：
M. Morimoto;H. Kayanne;O. Abe;M. McCulloch
中科院分区：
文献类型：
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作者：
M. Morimoto;H. Kayanne;O. Abe;M. McCulloch
利用珊瑚骨骼的锶/钙和氧同位素比值(δ18O)的耦合记录，定量估计了在某些情况下可转换为海表面盐度的表层海水的古海洋表面温度(Sst)和δ18O。分析了受东亚夏季风和冬季风影响的副热带西北太平洋基开岛的两个珊瑚化石，以研究中全新世与现代SST和SSS的差异。在6180cal yr BP，夏季和冬季的SST与今天大致相同；δ180夏季(+0.5PSU，+1.1PSU)和冬季(+0.2PSU，+0.6PSU)的海水和SSS值都高于现代值。在7010cal yr BP，夏季和冬季(−0.8和−0.6℃)SST都略有凉爽，而δ180海水和SSS在夏季(+0.3‰，+0.6PSU)和冬季(+0.8‰，+1.9PSU)都比现在值高。这些结果与西北太平洋中低纬度地区中全新世的其他海洋记录相一致。这样的区域条件表明，东亚夏季风和冬季风在全新世中期更为强烈，这可能是全新世中期日照制度的函数。
Coupled records of Sr/Ca and oxygen isotope ratios (δ18O) of coral skeletons have been used to produce quantitative estimates of paleo-sea surface temperature (SST) and δ18O of surface seawater that can in some cases be converted to sea surface salinity (SSS). Two fossil corals from Kikai Island in the subtropical northwestern Pacific, a location affected by East Asian summer and winter monsoons, were analyzed to investigate differences between mid-Holocene and present-day SST and SSS. At 6180 cal yr BP, SSTs were roughly the same as today, both in summer and winter; δ18Oseawater and SSS values were higher both in summer (+ 0.5‰, +1.1 psu) and in winter (+ 0.2‰, + 0.6 psu) than modern values. At 7010 cal yr BP, SSTs were slightly cooler both in summer and winter (−0.8 and −0.6 °C), whereas δ18Oseawater and SSS had higher values in summer (+ 0.3‰, + 0.6 psu) and in winter (+ 0.8‰, + 1.9 psu) than present-day values. These results are consistent with other marine records for the mid-Holocene of the low and midlatitudes in the northwestern Pacific. Such regional conditions indicate that the East Asian summer and winter monsoons were more intense in the mid-Holocene, which was likely a function of the mid-Holocene insolation regime.