Geomorphological and sedimentological traces of the 365 AD and 1303 AD tsunami impacts on the Korission Lagoon (Corfu Island, Greece) compared with tsunami simulation scenarios

Abstract

The AD 365 and the AD 1303 tsunamis are known extreme wave events that caused severe damage and fatalities along the coastlines of the eastern Mediterranean Sea. We analysed geomorphological and sedimentological data from the Korission Lagoon (Corfu Island, Greece) and compared them with results of numerical simulations. Washover fans and sediment cores reveal coarse-grained high-energy deposits intersecting prevailing lagoonal conditions. Geochemical and microfaunal analyses document a marine origin of these deposits. Results of radiocarbon dating suggest that they may correlate with the 365 AD and 1303 AD tsunami events. Numerical simulations of the 365 AD tsunami suggest the formation of several generations of tsunami waves during tsunami landfall. Erosion of the beach ridge and sedimentation in the lagoon increases with higher tsunami wave heights and flow velocities and is strongly controlled by the local topography. Generally, we found good agreement between field data and numerical simulation. Our model validation allows to investigate the morphodynamic response of the 365 AD tsunami along other coastlines of Greece. The current study demonstrates that numerical morphodynamic models can successfully be applied for a comparison with historical tsunami events, if tsunami deposits are well-preserved and sufficient information on the tsunami trigger mechanism is available.

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