【摘要】 研究了钻取于东帝汶海印尼穿越流出口处MD98-2172岩心沉积物,分析了浮游有孔虫表层水种Globigerinoides ruber和温跃层水种Pulleniatina obliquiloculata的Mg/Ca值,重建了30kaBP以来东帝汶海区的表层水温度和温跃层水温度。结果显示东帝汶海区末次冰盛期以来表层水温度距早全新世的最大温差约为4.2℃;冰消期间表层水温度有两次显著的降温事件,可分别与新仙女木事件和海因里希事件1对应;约15kaBP以来帝汶海表层水温度与南极大气温度记录同相位变化,说明热带海区与高纬度地区气候变化有着紧密联系。末次冰盛期以来温跃层水温度距早全新世的最大温差约为4℃;全新世温跃层水温度呈现出波动降低的过程,最大降温幅度约3℃;表层水温度和次表层水温度差值在全新世逐渐增加,指示了温跃层深度的持续变浅,这一变化可能与海平面上升、季风活动和厄尔尼诺-南方涛动事件影响的印度尼西亚穿越流次表层流增强有关。更多还原

【Abstract】 We studied the sediments of core MD98-2172 taken from the eastern Timor Sea within the main path of outflow of ITF.Sea surface temperature(SST)and thermocline water temperature(TWT)were reconstructed for the last 30 ka with Mg/Ca in shells of Globigerinoides ruber and Pulleniatina obliquiloculata.The SST records show a substantial glacial-interglacial cycle,with a maximum difference of 4.2℃during the last deglaciation,while the TWT shows a maximum of difference about 4℃throughout the period from last glacial maximum to early Holocene.Two cold events occurred during the deglaciation according to SST,corresponding to the Younger Drays(YD)and Heinrich event 1(H1)respectively.The SST records vary in phase with climatic change revealed by the Antarctic ice core.It suggests that there is a closely link between the tropical sea and the climatic change in high latitudes.A strongly decline of temperature(3 ℃)was seen in TWT records.The difference between SST and TWT increases during Holocene,indicating that the thermocline depth is getting shallower.We speculate that all of the sea level rise,monsoon activity and ENSO may have played important roles in influencing thermocline depth of the ITF outflow.更多还原