Thermocline Temperature and Hydrographic Proxy Records from Core E‑2, Northwestern Pacific

This dataset contains thermocline temperature and hydrographic proxy records from marine sediment core E‑2, recovered east of the Tokara Strait on the Pacific side of the Ryukyu Island Arc, northwestern Pacific. The records span approximately 19.0–1.1 ka BP and document changes in upper-ocean thermal structure and thermocline-water properties since the last deglaciation. The primary measurements are Mg/Ca ratios and stable oxygen isotope (δ¹⁸O) values of the thermocline-dwelling planktonic foraminifer Pulleniatina obliquiloculata. Mg/Ca ratios were converted to thermocline temperature using the calibration described in Dang et al. (2018). Foraminiferal calcite δ¹⁸O values were combined with Mg/Ca-derived thermocline temperatures to calculate seawater δ¹⁸O. The resulting values were subsequently corrected for global ice-volume changes to obtain δ¹⁸Osw-ice, which is used to characterize changes in thermocline hydrography and water-mass properties. A previously published alkenone-derived sea surface temperature record from the same core(Wu et al., 2012) is included as a supporting surface-ocean record. Together, the surface and thermocline records permit evaluation of changes in upper-ocean vertical thermal structure on orbital and centennial–millennial timescales.