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本次研究选取南海南部“太阳号”95航次17961-2柱状样(8°30.4′N,112°19.9′E,水深1795m,柱长10.3m)的175块样品进行浮游(Globigerinoides ruber)和底栖有孔虫(Cibicidoides wuellerstorfi)的氧碳稳定同位素及浮游有孔虫G.ruber壳体的Mg/Ca比值测定,再造了距今约140ka以来时间分辨率约800年的表层海水温度(SST)变化,揭示末次冰期南海南部的SST曾降温达约5℃,且存在类似Dansgaard-Oeschger(D/O)事件的千年尺度波动。将南海南部的研究结果与极地冰芯古气候记录进行对比,发现在千年时间尺度上南海南部SST的变化特征与南极冰芯的古气候变化相一致,而与格陵兰冰芯δ18O所展示的锯齿状形态D/O事件的变化不一样,且最近的两个末次冰消期南海南部SST与代表高纬冰盖体积大小的底栖有孔虫δ18O几乎同步变化,反映南海南部热带海区古气候变化的特殊性,为进一步研究低纬热带海区在全球古气候变化中的作用提供了新证据。
In this study, 175 samples from the South China Sea, No. 9561 17961-2 column (8 ° 30.4’N, 112 ° 19.9’E, water depth 1795m, column length 10.3m) were collected for Globigerinoides ruber (Cibicidoides wuellerstorfi) and the Mg / Ca ratio of the planktonic foraminifera G.ruber shell, and reconstructed the surface seawater temperature of about 800 years from the present about 140 ka SST) revealed that the SST in the southern South China Sea had been cooled down to about 5 ℃ in the last glacial period, and there was a millennium-scale fluctuation similar to the Dansgaard-Oeschger (D / O) event. Comparing the results from the southern South China Sea with those of the polar ice cores, it is found that the SST variations in the southern South China Sea coincide with paleoclimatic changes in the Antarctic ice cores on a thousand-year time scale, The changes of morphological D / O events are not the same, and the SSTs in the southern South China Sea and the benthic foraminiferal δ18O representing the volume of high latitudes change almost simultaneously in the last two periods of ice removal, reflecting the peculiarities of paleoclimatic changes in the tropical South China Sea , Which provided new evidence for further studying the role of low latitude tropical sea in the global paleoclimatic change.