Relative sea-level changes from tide-gauge records of eastern Asia mainland

Records from 22 tide-gauge stations along the mainland coast of eastern Asia document low-frequency vertical movements of the land perhaps biased by unevaluated changes of sea level. The land is rising (relative to sea level) as much as 5 mm yr −1 in the areas of massifs and ancient foldbelts and subsiding as much as 9 mm yr −1 in areas of Cenozoic basins and foldbelts. Although the tide-gauge records are sparse, inferences from them are supported by the stratigraphy and structure of the region, and by raised and submerged sea-level terraces. Thus, relative changes of sea level are heavily influenced here by tectonic and isostatic as well as eustatic factors, just as in Japan, Scandinavia, and North America where tide-gauge records are much more abundant. Higher frequency (2–25-yr periods) sea-level fluctuations show broad peaks between 2 and 4 yrs, and near 10 yrs. Some of these fluctuations correlate with behavior of the Kuroshio Current, which along with freshwater inflow dominates the hydrography of the eastern Asian continental shelves. Observations of water mass fluctuations are too sparse to identify direct causes of all high-frequency variability.