The Pacific meridional overturning circulation is thought to have a significant influence on global climate. However, the extent to which intermediate and deep circulations have changed in the Pacific Ocean since the Last Glacial Maximum (LGM) is not well known. At present, the South China Sea Deep Water (SCSDW) is fed by the upper Pacific Deep Water. Here we present new benthic foraminiferal δ¹³C and redox‐sensitive elemental data from a sediment core retrieved from the southern deep SCS to reconstruct the oxygenation history of the SCSDW since the LGM. Oxygenation records from the deep SCS and intermediate and deep waters in the Pacific Ocean demonstrate that the SCSDW deeper than 1,600 m has been sourced by the Pacific Deep Water since the LGM. Our data suggest that the well‐ventilated North Pacific Intermediate Water would not have influenced the SCSDW during cold stadials of the last deglacial period.

The depositional history of the lower Yangtze River and sea-level changes during Marine Oxygen Isotope Stage (MIS) 3 was established using three long drill cores from the northern Yangtze deltaic plain and southern Yellow Sea by using sedimentary analysis and AMS¹⁴C dates. Voluminous channel deposits of the lower Yangtze River in MIS 3 were found from the northern deltaic plain and offshore area, with a thickness of over 30 m. The thick channel deposits are characterized by massive medium-to-fine sand deposits with sporadic tidal influence. During MIS 3, the Yangtze River appears to have mainly migrated between the modern river mouth and middle Jiangsu coastal plain, and likely built a delta complex in the field of Yangtze Sand Shoal in northern East China Sea. A large sediment supply and rapid sea-level variations promoted rapid progradation of the delta onto the flat shelf. The highest sea levels during MIS 3 are estimated to have reached 25 ± 5 m below the present sea level.