Received: 16 Jul 2020 – Discussion started: 07 Aug 2020
Abstract. The dynamics of the East Asian Summer Monsoon (EASM) and their link to past societies during the Holocene are topics of growing interest. In this study, we present analyses of a ca. 6,000-year pollen record, as well as X-ray fluorescence (XRF) and grain-size data from the STP18-03 core sampled from Miryang in the Korean Peninsula, which spans ca. 8.3–2.3 ka BP. In-phase relationships of these proxies revealed an imprint of the Holocene Climate Optimum (HCO) during the early to mid-Holocene and subsequent drying toward the late Holocene in accordance with decreasing solar insolation. At centennial timescales, our study indicates wet conditions during ca. 8.3–7.5, 7.1–6.4, 6.0–4.8, and 3.6–2.8 ka BP, and a drier climate during ca. 7.5–7.1, 6.4–6.0, and 4.8–3.6 ka BP. Notably, our finding for ca. 6.4–6.0 ka BP contributes further evidence of a drying event in the Korean Peninsula during this period. We suggest that the Pacific Ocean played a role in the underlying mechanism of hydroclimate change in the region. A strong Kuroshio Current (KC) and long-term El Niño–Southern Oscillation (ENSO)-like variability in the Western Tropical Pacific (WTP) were closely linked to the influence of the EASM over the Korean Peninsula. In particular, dry phases during ca. 4.8–3.6 and 2.8–2.3 ka BP, which were synchronous with a more active ENSO, closely corresponded to lower population levels according to a summed probability distribution (SPD) of archaeological records assembled in the Korean Peninsula. This finding implies that past human societies of Korea were highly vulnerable to climate deterioration caused by precipitation deficits.
Using multiple proxies, this study reconstructs hydroclimate change of the Korean Peninsula between ca. 8.3 and 2.3 kiloyears before present. In coastal region of East Asia, variation between wet and dry phases has been closely connected with sea-surface temperatures (SSTs) of the western Pacific Ocean. Besides, our results are also coherent with estimated prehistoric population levels in the Korean Peninsula, implying great sensitivity of past human societies to precipitation changes.
Using multiple proxies, this study reconstructs hydroclimate change of the Korean Peninsula...