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珊瑚生长率是记录海洋表层海水温度(SST)的重要指标之一。本文在测量西沙永兴岛海域1个现代滨珊瑚(Porites lutea)和4个中~晚全新世滨珊瑚样品生长率基础上,定量重建了中晚全新世5个特征时段的SST:1887~2007A.D.(27.27℃)、1993~1936a B.P.(26.73℃)、2985~2904a B.P.(26.5℃)、4004~3962a B.P.(26.8℃)和5514~5398a B.P.(27.0℃)。这些结果表明5.5~1.9ka B.P.期间西沙海域SST总体上呈下降趋势,与中国大陆的平均温度基本同步变化。西沙海域中晚全新世SST的降低趋势受东亚夏季风强度减弱的控制,也可能与这一时期逐渐活跃的ENSO存在联系,而岁差引起的北半球太阳辐射量的减少可能是SST变化的根本驱动因素。
Coral growth rate is one of the important indicators of sea surface temperature (SST). Based on the measurements of the growth rate of one modern Porites lutea and four middle-late Holocene samples of coral in Yongxing Island, Xishuangbanna, SST: 1887 ~ 2007A .D. (27.27 ° C), 1993-1936a BP (26.73 ° C), 2985- 2904a BP (26.5 ° C), 4004-3962a BP (26.8 ° C) and 5514- 5398a BP (27.0 ° C). These results indicate that the SST in Xisha area during the period of 5.5-1.9 ka B.P. is generally declining, which is basically synchronous with the average temperature in mainland China. The decreasing trend of SST in the mid-late Holocene in the Xisha Sea is controlled by the weakening of the East Asian summer monsoon and may also be related to the active ENSO in this period. The decrease of solar radiation in the Northern Hemisphere caused by precession may be the fundamental driving factor of the SST .