Traces of repeated tsunami landfall in the vicinity of Limnothalassa Moustou (Gulf of Argolis – Peloponnese, Greece)
Ntageretzis, Konstantin; Vött, Andreas; Fischer, Peter; Hadler, Hanna; Emde, Kurt; Röbke, Björn Roman; Willershäuser, Timo
published: Dec 1, 2015
The Gulf of Argolis is located close to the Hellenic Volcanic Arc and the Hellenic Trench and thus faces a high risk to be affected by seismo-tectonically induced tsunami events. Historical accounts as well as modern tsunami catalogues document that the southern coasts of the Peloponnese were repeatedly affected by tsunamis. This is, however, the first study revealing geoscientific evidence on past extreme wave impact on the Gulf of Argolis. The low-lying near-coast limnic-lagoonal area around Limnothalassa Moustou, located in the central-western margin of the gulf, was investigated by means of sedimento- logical, geomorphological, geochemical and micropalaeontological methods in search of palaeotsunami fingerprints in the Holocene stratigraphical record. Our investigations have brought to light that the low-energy environments around Limnothalassa Moustou were affected by three tsunami impacts. The youngest event most possibly refers to the historically well-known tsunami from 1303 AD that hit wide parts of the eastern Mediterranean, especially the Peloponnese. Tsunami inundations were accompanied by complex backwash flow dynamics resulting in the deposition of coarse-grained coastal and fluvial material. The sedimentary environments hit by the youngest tsunami landfall soon recovered after tsunami impact which is documented by homogeneous fine-grained sediments in the uppermost parts of all vibracores. These sediments are typical of quiescent low-energy marsh environments that existed in wide parts of the investigated back-beach area at least during the last 500 or so years.