Reef coral δ15O thermometer in Hainan island waters,South China Sea

P736.4; An 18-year-long (1981-1998) study was conducted in Hainan Island wa ters (22°20＇N, 110°39′E) to determine the relationship between δ18O in skeletal arag onite carbonate and sea surface temperature (SST) in porites lutea of reef-building corals. δ18O values in skeletal aragonite carbonate were measured by means of mass spectrometry. Coral samples grew at 5m depth at Longwan Bay. Monthly measure ments of the SST from 1960 to 1998 were taken at Qinglan Bay adjacent to the place of the collected samples. The thermometer shows that SST=-4.16 δ18OpDB + 4.9 (r=0.80) and dδ18O/dT=-0.24 permil/°C. The δ18O thermometer is strongly influ enced by the rainfall and runoff. Using the thermometer, the SST in the past hundred years with monthly resolution will be reconstructed and the climatic change in the northern area of South China Sea will be hindcasted