HR: 16:15h
AN: PP24A-02    [Abstracts]
TI: 1.1 Million Years of Environmental Change in the Sea of Okhotsk
AU: * Nuernberg, D
EM: dnuernberg@ifm-geomar.de
AF: IFM-GEOMAR, Leibniz-Institut f�r Meereswissenschaften, Wischhofstr. 1-3, Kiel, 24148 Germany
AU: Tiedemann, R
EM: rtiedemann@ifm-geomar.de
AF: IFM-GEOMAR, Leibniz-Institut f�r Meereswissenschaften, Wischhofstr. 1-3, Kiel, 24148 Germany
AB: Based on sedimentary records from the central Sea of Okhotsk, we reconstruct the closely coupled glacial/interglacial changes in terrigenous flux, marine productivity, and sea ice coverage over the past 1.1 Ma. The correspondance of our sedimentary records to the China loess grain size record (China Loess Particle Timescale, CHILOPARTS) suggests that environmental changes in both the Sea of Okhotsk area and in SE Asia were closely related via the Siberian atmospheric high pressure cell. During full glacial times, our records point to a strong Siberian High causing northerly wind directions, the extension of the sea ice cover, and a reduced Amur River discharge. Deglacial maxima of terrigenous flux were succeeded by or synchronous to high-productivity events. Marine productivity was strengthened during glacial terminations due to an effective nutrient utilization at times of enhanced water column stratification and high nutrient supply from fluvial runoff and sea ice thawing. During interglacials, SE monsoonal winds prevailed analogous to the today's summer situation of a pronounced Mongolian Heat Low and a strong Hawaian High. Strong freshwater discharge induced by high precipitation rates in the Amur drainage area, and a seasonally reduced and mobile sea ice cover favored marine productivity (although being considerably lower than during the terminations), and a lowered flux of ice-rafted detritus.
DE: 4267 Paleoceanography
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting