Terrestrial – Ocean environmental change in the northwestern Pacific from the glacial times to Holocene

The Mixed Water Region (MWR) between the Oyashio Current and the Kuroshio Extension and surrounding terrestrial region have been affected by the global climatic change. The sedimentary core KR02-15 PC6 collected at 40°23.8871′N, 143°29.8663′E in the MWR provides detailed records of pollen and spores and alkenone sea surface temperature (SST) during the last 15 kyr, showing that both ocean and terrestrial environments have been appreciably linked. Abundance of Picea, a proxy for terrestrial cool climate, fluctuated, coinciding with the alkenone-SST change during the interstadial period (15.0–7.7 cal kyr B.P.). Alkenone-SST increased to the modern level at 8.0 cal kyr B.P. and remained almost constant until 2.0 kyr B.P. while the terrestrial warming still continued until 4.0 cal kyr B.P. The rainfall under terrestrial warm condition increased gradually from 7.9 cal kyr B.P. and rapidly from 2.0 cal kyr B.P. Both terrestrial and marine environments cooled down during the last 2 kyr possibly due to the intensified cold Oyashio Current.

Research highlights► Detailed records of alkenone sea surface temperature (SST) and pollen and spores during the last 15 kyr showed that both ocean and terrestrial environments have been highly linked in the Mixed Water Region (MWR) between the Oyashio Current and the Kuroshio Extension in the North Pacific. Alkenone-SST increased during the interstadial period (15.0 - 7.7 cal kyr B.P.) and reached the modern level at 8.0 cal kyr B.P. and remained almost constant until 2.0 cal kyr B.P. and cooled down to the modern condition. The rainfall under terrestrial warm condition increased gradually from 8.0 cal kyr B.P. and rapidly from 2.1 cal kyr B.P.