Global sea-level rise and the disappearance of tidal notches

摘要

The recent rise in global sea level is causing the disappearance of an important geomorphoiogical sea-level indicator, the tidal notch. Tidal notches have often been used in carbonate coasts for Quaternary and iate Hoiocene sea-ievel reconstructions and estimation of tectonic movements, especially in uplifting areas. In this paper, we review the rates of tidal notch development, and examine the recent gradual depletion of this feature, durxg at least the last century, and its relation to the increasing rates of sea-level rise. Some examples of tidal notch development are provided with fossil submerged notches from Greece. Although tidal notches are no longer forming in the present-day mid-littoral zone, underwater marks on carbonate cliffs may sill provide evidence of submerged tidal notches corresponding to former sea-level positions, or of recent vertical shoreline displacements of seismic origin.