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The Sea of Japan is a unique marginal sea in the northwest Pacific Ocean, which is known as "miniature ocean". Constrained by four shallow straits communicating with surroundings seas, it is very sensitive to glacio-eustatic sea level changes. Also, it is located beneath the East Asia Monsoon, which affects the hydrography of surface waters, deep circulations and accumulation of terrigenous materials. The presence of seasonal ice also plays a role in controlling the local distributions of terrigenous materials and deep ventilation in the Sea of Japan. An increasing body of studies revealed pronounced changes in past ocean environment in the Sea of Japan since the late Quaternary. However, it remains elusive for past environment changes in the western Sea of Japan. In this study, we investigate the lithology, rare earth elements and radiogenic isotopes of sediment core LV53-18 retrieved from the western Sea of Japan since the last glaciation.The contents of coarse fraction of sediment grain size suggest an advance in sea ice cover during the last deglaciation and the early Holocene (15-8 ka) and potential perennial sea ice cover during Heinrich Stadial (HS) 1 and HS2. The variation in sea ice cover is explained by changing strength of East Asian Winter Monsoon (EAWM). On millennial timescales (HS2, HS1 and Younger Dryas), our grainsize data shows a reverse correlation between the EAWM and the East Asian Summer Monsoon (EASM), indicating by Chinese stalagmite δ18O record, and it is ascribed to the slowdown of Atlantic Meridional Overturning Circulation (AMOC). The brine rejection related to sea-ice generation enhances local deep ventilation.Both the concentration of ∑REEs and positive Eu anomaly (1.2~1.4) reveal a sustained contribution of calcium-rich volcanic materials after 8 ka, which coincides with the onset and intensity of Liman Cold Current during the sea-level highstand. Furthermore, the 87Sr/86Sr values (0.706347 to 0.711713) decrease after 8 ka while εNd (-5.09 to -2.45) are more radiogenic, which further corroborate the presence of volcanic materials. On the basis of a binary mixture of volcanic material and upper crust, we estimated qualitatively the relative contributions of these two end-members. In summary, our study underlines the importance of EAWM in controlling the environment in the western Sea of Japan and reveals increasing volcanic contribution since 8 ka, which is related to the intensity of Liman Cold Current.Note: This study was supported by the National Natural Science Foundation of China (Grant No. 41420104005, U1606401) and National Program on Global Change and Air-Sea Interaction (GASI-GEOGE-04).

Grain size, clay minerals and major and trace elements of surface sediment samples collected from the East Siberian Arctic shelf are analyzed. Based on factor analysis and cluster analysis the study area is classified into four provinces, the main sediment sources of each provinces is discussed. The results show: province I covers the coastal estuary of the Kolyma River and the Indigirka River. The sediments are mainly composed of silt and sandy silt, and characterized by highest content of SiO2, TiO2, Zr, Sr and low content of other elements. Illite is dominant which accounting for 70% of the whole clay minerals. This area is strongly influenced by terrestrial sources from the Kolyma River and the Indigirka River. ProvinceⅡis located in the middle of the East Siberian Sea, where the sediments are generally silt and mud. The content of Al2O3, K2O, MnO and Ni are relatively high. Clay minerals composition is similar to Province I, but MnO/TiO2 ratio is higher. The sediments in this area are mainly fine-grained imported by rivers, which are also influenced by sea ice process. As the distance increasing offshore, the content of marine authigenic components begin to increase. Province Ⅲ is located in the northern East Siberian Sea, sediments there are mainly mud. Elements such as Al2O3, K2O, V, Li reach the maximum value in this area. The content of illite is the lowest, semctite and kaolinite reach the maximum (>10%). Fine sediments in this area are probably influenced by Atlantic waters and the Beaufort Gyre. Province Ⅳ is located in Chukchi Sea where the sediments consist of silt and sandy silt. Elements are characterized by higher contents of CaO, P2O5, and the content of Chlorite reach peak (>20%). Sediments in this area are significantly influenced by the Pacific inflow water. Note: This study was supported by the Marine S&T Fund of Shandong Province for Qingdao National Laboratory for Marine Science and Technology (Grant No. 2018SDKJ0104-3) , National Natural Science Foundation of China (Grant No. U1606401，41722603) and National Program on Global Change and Air-Sea Interaction (GASI-GEOGE-03)

The deep ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO2 levels on millennial timescales is poorly constrained. Here, we investigate a suite of geochemical proxies in a sediment core from the northern and middle Okinawa Trough to understand variations in intermediate-water ventilation of the subtropical North Pacific over the last 50,000 years (50 ka). Our results suggest that enhanced mid-depth western subtropical North Pacific (WSTNP) sedimentary oxygenation occurred during cold intervals during the last deglaciation and last glaciation, while oxygenation decreased during the Bölling-Alleröd (B/A) and warm interstadials. The enhanced oxygenation during cold spells is linked to the intensified North Pacific Intermediate Water (NPIW), while interglacial increase after 8.5 ka is linked to an intensification of the Kuroshio Current due to strengthened northeast trade winds over the tropics. The enhanced formation of NPIW during Heinrich Stadials was likely driven by the perturbation of sea ice formation and sea surface salinity oscillations in high-latitude North Pacific. The diminished sedimentary oxygenation during the B/A and interstadials due to decreased NPIW formation and enhanced export production, indicates an expansion of oxygen minimum zone in the North Pacific and enhanced CO2 sequestration at mid-depth waters. We attribute the millennial-scale changes to intensified NPIW and enhanced abyss flushing during deglacial cold and warm intervals, respectively, closely related to variations in North Atlantic Deep Water formation. Out study extends the millennial-scale links between ventilation in the subtropical North Pacific Ocean and the Atlantic Climate into the last glaciations, highlighting the key roles of Atlantic Meridional Overturning Circulation in regulating the North Pacific environment at millennial timescales. Note: Financial support was provided by the National Program on Global Change and Air-Sea Interaction (GASI-GEOGE-04) and by the National Natural Science Foundation of China (Grant Nos.: 41876065, 41476056, and U1606401).

Lower glacial atmospheric CO2 concentrations have been attributed to carbon sequestration in deep oceans. However, potential roles of voluminous subtropical North Pacific in modulating atmospheric CO2 levels on millennial timescale are poorly constrained. Further, an increase in respired CO2 concentration in the glacial deep ocean due to biological pump generally is coeval with less oxygenation in the subsurface layer. This link thus offers a chance to visit oceanic ventilation and the coeval export productivity based on redox-controlled sedimentary geochemical parameters. Here we investigate a suite of sediment geochemical proxies to understand the sedimentary oxygenation variations in the subtropical North Pacific (core CSH1) over the last 50 thousand years (ka). Our results suggest that sedimentary oxygenation at mid-depths of the subtropical North Pacific intensifies during the episodes of late glacial (50–25 ka), Last Glacial Maximum (LGM) and also the interval after 8.5 ka, especially pronounced for the North Atlantic millennial-scale abrupt cold events of the Younger Dryas, Heinrich Stadial (HS) 1 and 2. On the other hand, oxygen-depleted seawater is found during the Bölling-Alleröd (B/A) and Preboreal. Our findings of enhanced sedimentary oxygenation in the subtropical North Pacific is aligned with intensified formation of North Pacific Intermediate Water (NPIW) during cold spells, while the ameliorated sedimentary oxygenation seems to be linked with the intensified Kuroshio Current since 8.5 ka. In our results, diminished sedimentary oxygenation during the B/A indicates an enhanced CO2 sequestration at mid-depth waters, along with slight increase in atmospheric CO2 concentration. Mechanistically, we speculate that these millennial-scale changes were linked to the strength of North Atlantic Deep Water, leading to intensification of NPIW formation and enhanced abyss flushing during deglacial cold and warm intervals, respectively. Enhanced formation of NPIW seem to be driven by the perturbation of sea ice formation and sea surface salinity oscillation in high latitude North Pacific through atmospheric and oceanic teleconnection. During the B/A, decreased sedimentary oxygenation likely resulted from an upward penetration of aged deep water into the intermediate-depth in the North Pacific, corresponding to a resumption of Atlantic Meridional Overturning Circulation.