Multiple Submerged Tidal Notches: A Witness of Sequences of Coseismic Subsidence in the Aegean Sea, Greece

In some islands of the Aegean, there is evidence of the occurrence of repeated rapid subsidences during the Late Holocene. In this paper, the shape of tidal notches that may be well-preserved underwater is recalled in order to reconstruct sequences of coseismic subsidences and other relative sea-level changes, which occurred during, at least, the last few millennia. A reanalysis of the published measurements of submerged tidal notches in several islands reveals that subsidence trends in many areas of the Aegean are not continuous with gradual movement but, also, are the result of repeated coseismic vertical subsidences of some decimetres at each time. The estimated average return times are of the order of approximately some centuries to one millennium. Although the results cannot be used for short-term predictions of earthquakes, they may provide useful indications on the long-term tectonic trends that are active in the Aegean region.

Automated summary

This paper reconstructs sequences of coseismic subsidences and relative sea-level changes in the Late Holocene Aegean islands through the shape of tidal notches. The analysis reveals that the subsidence trends are not continuous with gradual movement, but rather result from repeated coseismic vertical subsidences. The estimated average return times are approximately some centuries to one millennium, providing useful indications on the long-term tectonic trends in the Aegean region.