Holocene palaeotsunami imprints in the stratigraphical record and the coastal geomorphology of the Gialova Lagoon near Pylos (southwestern Peloponnese, Greece)
Willershäuser, Timo; Vött, Andreas; Hadler, Hanna; Ntageretzis, Konstantin; Emde, Kurt; Brückner, Helmut
published: Dec 1, 2015
The coastal area around the Gialova Lagoon (southwestern Peloponnese, Greece) is directly exposed to the highly tectonically active Hellenic Trench. As known from historical sources, the coastline was repeatedly affected by tsunamigenic impacts. Detailed geo-scientific studies were carried out in the environs of the Gialova Lagoon in search of high-energy event deposits. Geomorphological, sedimentological and geochemical methods were applied in order to identify Holocene tsunami events and reconstruct the palaeogeographical evolution of the area based on 8 terrestrial vibracorings. Microfossil studies were applied along a transect of three vibracores to decipher detailed changes in the palaeoen-vironmental setting. Our results show that the palaeogeographical evolution of the Gialova Lagoon was strongly affected by high-energy impacts. Coarse-grained allochthonous sediments of marine origin were found intersecting low-energy lagoonal and limnic muds. Based on sedimentary characteristics, the local (palaeo-) geomorphological setting and the geomorphodynamic potential of modern-day storms, we conclude that the identified high-energy events were associated with tsunami impacts. Radiocarbon datings allowed age estimations of six tsunami generations that took place between the 4th millennium BC and medieval times. Geomorphological characteristics of the study area such as the Voidokilia washover fans and beachrock structures along the coastline also provide evidence of repeated tsunamigenic landfalls.