Palaeoceanography of the Japan Sea Across the Mid‐Pleistocene Transition: Insights From IODP Exp. 346, Site U1427. Issue 1 (12th January 2022)

• Record Type: Journal Article
• Authors: Felder, Sonja; Sagawa, Takuya; Greaves, Mervyn; Leng, Melanie J.; Ikehara, Ken; Kimoto, Katsunori; Hasegawa, Siro; Wagner, Thomas; Henderson, Andrew C. G.
• Is Part Of: Paleoceanography and paleoclimatology. Volume 37:Issue 1(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-12
• Subjects: IODP Exp. 346 -- Site U1427 -- Japan Sea palaeoceanography across the mid‐Pleistocene transition -- Uvigerina oxygen isotope and trace element (Mg/Ca) records -- Mg/Ca‐temperature core‐top calibration for Uvigerina -- Japan Sea δ18O of seawater record; Paleoceanography -- Periodicals; Paleoclimatology -- Periodicals; 551.46
• DOI: 10.1029/2021PA004236
• Languages: English
• ISSNs: 2572-4517

Abstract

Abstract: Large‐scale atmospheric circulation patterns, such as the East Asian monsoon, have been proposed as possible feedbacks of the mid‐Pleistocene transition (MPT). Marine sediments of the Japan Sea (JS) record variations in the East Asian monsoon over long timescales and may be crucial for understanding of the MPT. To interpret these sediments correctly an understanding of the JS palaeoceanography is necessary. So far, the JS palaeoceanography has been extrapolated across the MPT from studies of the most recent glacial‐interglacial cycles. These suggest a good connection and unrestricted water‐mass exchange with the open ocean during interglacial sea‐level highstands, while during glacial sea‐level lowstands the JS is nearly isolated. Glacial isolation often results in poor carbonate preservation and unusually low oxygen isotope (δ 18 O) ratios from low‐saline/low‐δ 18 O waters accumulating in the basin. Using the sediments of Integrated Ocean Drilling Program (IODP) Site U1427, a shallow‐water site in the southern JS, we present a continuous foraminiferal δ 18 O record encompassing the MPT. This record shows the JS‐typical low glacial δ 18 O values in the late phase of the MPT, across Marine Isotope Stages (MIS) 24‐17, while earlier MPT glacials, across MIS 39‐25, are characterized by high δ 18 O values. We propose that high glacial δ 18 O values are the result of an improved connection between the shallow, southern JS and adjacent ocean during early MPT glacials. The impact of this palaeoceanographic mode, if continued to deep‐water sites, would make the interpretation of dark/light sediment layers as glacial/interglacial deposits uncertain. Key Points: A high‐resolution, continuous benthic foraminiferal oxygen isotope record is presented using sediments of IODP Site U1427 (Exp. 346) MIS 24‐17 are characterized by the glacial near isolation of the Japan Sea, while for stages 39‐25 an improved connection is suggested Presenting a new core‐top Mg/Ca‐temperature calibration for Uvigerina spp . from the Japan Sea and revised age model for IODP Site U1427