LATE QUATERNARY PALEOCEANOGRAPHIC RECORDS IN THE SOUTHERN OKHOTSK SEA

The Sea of Okhotsk is the second largest marginal sea of the Pacific, and plays a significant role in the hydrology of the northwestern Pacific. We processed and analyzed multi-proxies of the sediment of core T00 from the southern Sea of Okhotsk. The results show that the environmental changes in the Sea of Okhotsk are characterized by a coupled interplay between seasonal sea ice dynamics, atmospheric circulation patterns, terrigenous flux, and surface productivity during late Quaternary. The stratigraphic MIS1 to MIS7 since~250 ka of core T00 has been recognized by comparing the percentage curve of Cycladophora davisiana with the LR04 benthic δ¹⁸O stack. The higher percentage of C.davisiana during interglacial intervals indicates that the Sea of Okhotsk is the source region of the North Pacific Intermediate Water Mass. The primary productivity in the southern Sea of Okhotsk, indexed by contents of opal and total organic carbon, is relatively higher during interglacials than during glacials, and increases rapidly during deglacials. The oceanic origin of the organic matters in core T00 is figured out by the C/N ratio analysis. The content of terrigenous coarse grain in the Sea of Okhotsk is lower in glacials than in interglacials and increases rapidly in deglacials.