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This study traces coastal sand dune development processes in East Asia during the Holocene to understand climate and environmental changes. We used optically stimulated luminescence (OSL) dating to examine periods of activation and stabilization of dunes along the western coast of the Korean Peninsula. The results from the Taean Chollipo, Seocheon Dasari, and Gochang Sabanri dunes were then compared with those from previous studies to establish a broad understanding of coastal dune development in this region. Sedimentation rates were calculated for the three dunes, and their development periods were classified through statistical analysis that included data from previous studies. We defined five main periods of late Holocene dune development (<0.1 ka, 0.2–0.5 ka, 1.2–2.0 ka, 2.5–3.2 ka, and 5.5–6.5 ka). These correlated to periods of sea level decrease and global cooling determined by ice rafted debris records. We concluded that the development of coastal dunes in western Korea was influenced by sea level decreases, and global cooling events were enhanced by the East Asian winter monsoon. In addition, human activity increases also contributed to the development of the dunes. This study showed how coastal sand dunes can be evaluated as important indicators of global climate change. These results improved our understanding of how paleoclimate changes affected environmental conditions in East Asia and how coastal dune development periods can be used to reconstruct paleo-environmental conditions. • Coastal sand dunes are developed along the western coast of the Korean Peninsula. • Five main periods of late Holocene dune development were determined by OSL. • Main periods were -less than 0.1, 0.2–0.5, 1.2–2.0, 2.5–3.2, and 5.5–6.5 ka. • Main periods were agreed with sea level decrease and global cooling in the Holocene. [ABSTRACT FROM AUTHOR]

Abstract: Marine isotope stage 3 (MIS3), spanning from 25 to 60ka BP, was a time of substantial environmental change that included changes in the global ice volume and atmospheric composition, with resultant regional climate changes. To understand past vegetation responses to such environmental changes in Korea, we estimated the abundance of C3 and C4 plants using the C/N and carbon isotope ratios of sedimentary organic matter. The MIS3 sedimentary unit at the Cheollipo site, located in a western coastal area of Korea, is characterized by a dark to light gray colored sedimentary unit (3.05 to 5.05m in elevation, MIS3), which is between an underlain oxidized yellowish sedimentary unit (<3.05m in elevation) and an overlain oxidized yellowish sedimentary unit (>5.05m in elevation). The estimated abundance of C4 plants varied between 60 and 10% during the MIS3. The suborbital-scale variation in the estimated percentage of C4 plants was similar to those reported in continental ice volume and the East Asian monsoon intensity, suggesting that C4 plants prevailed under colder and drier conditions (intensified winter monsoon), whereas C3 plants have favored a warmer and wetter climate (intensified summer monsoon). Compared with high latitude regions (e.g., Chinese Loess Plateau and Lake Baikal) where low summer temperature suppressed aridity and pCO2 influences during the last glacial period, vegetation change in Cheollipo area may have more sensitively responded to aridity change which had been affected by the summer/winter monsoon intensity. The climate change in the western coastal area (Yellow Sea side) of Korea during the late Pleistocene may have been controlled by regional climate change coupled with continental ice volume change. [ABSTRACT FROM AUTHOR]