Reconstruction of East-Asian Monsoon-Climate Variability With Ultra-High-Resolution Sediment-Color Records From the South China Sea

C Buehring (Graduiertenkolleg Dynamik globaler Kreislaeufe, Universitaet Kiel, D-24118 Kiel, Germany; ph. 431-880-2866; fax 431-880-4376; Internet: cb@zaphod.gpi.uni-kiel.de); M Sarnthein (Geologisch-Palaeontologisches Institut, Universitaet Kiel, D-24118 Kiel, Germany; ph. 431-880-2866; fax 431-880-4376; Internet: ms@zaphod.gpi.uni-kiel.de)

In the South China Sea (SCS) the various sedimentation regimes along the continental margins of China, Vietnam, and north-east Borneo are linked to strong monsoonal control. The close neighborhood to the Pacific and its Warm Pool / ENSO phenomenon may be also important. To reconstruct short-term variations in the sediment record of climate change we use a digital analysis of sediment color with a sampling resolution of 1 mm and a conventional SpectroPhotometer. This technique was employed to cores from recent SONNE cruises 95 and 115. The color-code logs closely parallel the long-range variations of some other geochemical records, especially the d18O-records and, in part, the % CaCO3 curves. Thus the color records may finally lead to a clear increase of time resolution, at sedimentation rates of 10-80 cm/ky up to a decadal range or less. Based on power spectra of the ultra high-resolution color records we are tracing high frequency periodicities of the monsoon, enforced by mechanisms such as sun-spot and ENSO cycles and the phase relationships with other climatic time series and climatic forcings.