Toward establishing a maritime proxy record of the East Asian summer monsoons for the late Quaternary

An astronomically tuned late Quaternary planktic foraminiferal δ18O record of Site MD972142 (12°41.33′N, 119°27.90′E; 1557 m water depth) in the southeastern South China Sea was established. The difference in δ18O between MD972142 and ODP792 of the Sulu Sea is regarded as a maritime proxy of the summer monsoon intensity over the South China Sea and Southeast Asia. The profile of this maritime proxy matches well with the summer monsoon index obtained from the terrestrial record of Louchuan, central Chinese Loess Plateau. The amplified planktic δ18O signals of the South China Sea relative to the Sulu Sea record are partly caused by the changing intensities of the East Asian Monsoons at the glacial–interglacial time-scale throughout the late Quaternary.