南极普里兹湾海域的近现代沉积速率

Modern Sedimentation Rates in Prydz Bay,Antarctic

利用中国第21次南极科学考察获得的普里兹湾海域的沉积物样品,运用沉积地层同位素210Pb测年技术,探讨了该海域沉积物的近现代沉积速率及其影响因素。研究结果表明,南极普里兹湾海域的近现代沉积速率变化范围在0.47～1.88 mm/a之间,平均值为1.06 mm/a,高于南极罗斯海而低于威德尔海,总体上与南、北极多个海区的沉积速率相当。在湾内和冰架边缘区,沉积速率主要受上层海洋生物生产的影响,而在湾口浅滩区沉积速率则主要受底栖生物的影响。此外,水流、水体稳定度、冰封期长短和海底地形等条件也对沉积速率产生一定的影响,沉积速率的分布是多种因素共同控制的结果。在生物量较高、水体条件较为稳定的湾内中心区域,沉积速率较高,而冰架边缘区的沉积速率则较低。

Using the ^210Pb dating methods in the sediment cores, the modern sedimentation rates in Prydz Bay （Antarctic） are estimated. The results show that the modern sedimentation rates are mainly controlled by marine primary productivity in upper water and benthos in surface sediment. Furthermore, the modern sedimentation rates are also controlled by water stability and submarine topography. The values are 0.47 - 1.88 mm/a and the average value is 1.06 mm/a. The sedimentation rate is higher than that in Ross Sea but lower than that in Weddell Sea. The highest value occurred in central area of the bay where the sea water is much more stability. The modem sedimentation rates in adjacent continental shelf are much lower.