VARIATION IN SURFACE AND THERMOCLINE TEMPERATURE OF THE EASTERN TIMOR SEA FOR THE LAST 30 KA AND ITS PALEOCEANOGRAPHIC IMPLICATIONS

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.