Short-Term Vertical Datum Variability and Vertical Crustal Movements in East Asia

Field biological and geomorphological observations in certain East Asia coasts permit definition of Mean Sea Level (MSL) with an accuracy of ∼10 cm, that is, a vertical geodetic datum, as well as recognition of the MSL of fossil shorelines, up to a few thousand years old, mainly associated with tectonic/seismic effects. Subsidence produced by compaction of nearly-surficial strata seems also to be a usual effect. These data indicate that datum variability is a widespread effect in East Asia, time-dependent even at time scales affecting engineering works, but only in a few cases fully predictable.