Holocene relative sea-level changes inferred from multiple proxies on the west coast of South Korea

Understanding past relative sea-level (RSL) changes is crucial for predicting future coastal evolution, particularly within the context of accelerated melting of polar ice sheets due to global warming. RSL records are scarce in many regions along the Pacific coast. Here, we present a Holocene RSL curve for the west coast of South Korea based on detailed analyses of four sediment cores and the synthesis of existing sea-level index points without correction by tectonic, sediment compaction and other effects. Our record shows that the local sea level rose rapidly during the early Holocene and then fell gradually toward the present position during the late Holocene. An apparent sea-level highstand of ca. 1-2 m occurred 7-4 cal kyr B.P. A rapid sea-level rise of ~1.4 cm yr−1 during the early Holocene is a manifestation of polar ice sheet decay, while the apparent mid-Holocene sea-level highstand appears to be a signal of the hydro-isostasy of the far-field continental shelf. The result was confirmed by a glacial isostatic adjustment (GIA) model. Holocene RSL change on the west coast of South Korea was closely linked to global temperature and ice sheet decay, especially during the early Holocene. There is a close relationship between sea-level change in the study area and Laurentide Ice Sheet (LIS) decay.