The Disappearance of Helike-Classical Greece—New Remote Sensing and Geological Evidence

Abstract

Helike, the Achaean Dodecapolis capital, in the Corinth Gulf, Greece, was, according to historical sources, devastated and disappeared from sight during an earthquake followed by sea invasion on to land in 373/372 B.C. A marine remote sensing survey, which was carried out to examine a landslide following a 6.2 R earthquake in 1995, that affected the coastal and near-shore delta plain zone on which Helike stood, accompanied by onshore borehole data, enabled us to postulate the geological processes leading to the Helike catastrophe. Helike was initially leveled during a 6 to 6.7 R earthquake; it is postulated to have then submerged following a translational landslide caused by liquefaction. This Helike catastrophe model is consistent with historical sources and current views regarding the expected geological hazards magnitude in the Gulf.

Earthquake-triggered landslides and mudflows: Was this the wave that engulfed Ancient Helike?

“…Was it submarine fault slip or the triggering of a submarine landslide that triggered any tsunami? The absence of tsunami deposits in any geological archive might be explained because deposits were eroded by the later mudflow, or the runup of the tsunami in the literary sources is exaggerated (see also discussion in Ferentinos et al, 2015;Walter, 2017). Moreover, geomorphological observations from modern tsunami deposits show extensive deposition of large boulders forming significant thickness deposits (Dawson, 1994).…”

“…et al, 1988;Marinatos, 1960;Mouyaris et al, 1992;Papazachos and Papazachou, 1989;1997;Perrou et al, 2013), or the event resulted from reactivation of multiple fault segments (Console et al, 2015;Lambotte et al, 2014). In addition, together with the tremendous earthquake it has been proposed that Ancient Helike was drowned due to a huge translational slide, which caused 10 m of subsidence of the city below its pre-earthquake elevation, bringing it below sea level and thus amplifying the effects of tsunani inundation (Ferentinos et al, 2015;Leonards et al, 1988;Marinatos, 1960;Papadopoulos, 1998;2003;Papanastassiou, 2002). In one interpretation, this subsidence/inundation scenario is even more strengthened by the suggestion of a landslide causing subsidence of the city just before the 373 BC earthquake.…”

“…Previous authors have assumed, based on the literary sources, what we term the coastal disaster model (CDM). This proposed tremendous changes in the coastal zone related to co-seismic earthquake subsidence and tsunami inundation, linked to strong seismicity hosted by the Helike Fault (Doutsos and Poulimenos, 1992;Engel et al, 2016;Ferentinos et al, 2015;Psarropoulos and Gkantona, 2020). This long-standing assumption considers that the combination of earthquake shaking and building collapse with tsunami inundation in the coastal zone caused mass death of the inhabitants.…”

Possibilities of Using Remote Sensing in Archaeological Research in Bengal Delta in Bangladesh - A Human-Influenced Alluvial Terrain

“…Mehdi [64] concluded, based on the available data on sediments, that the buried channels, identified from Landsat ETM+ and SRTM and ASTER DEM data, at depths 6-13m were last active between 6 and 3 Ka B.P., when they supported the archaeological settlements along their banks. Ferentinos [65] opined that geological evidence for disappeared habitation sites can be identified from remote sensing.…”

Προστασία Και Ανάδειξη Ενάλιων Αρχαιολογικών Θέσεων Στην Ελλάδα

“…Παρόμοια έρευνα πραγματοποιείται το 1995 από το Εργαστήριο Θαλάσσιας Γεωλογίας και Φυσικής Ωκεανογραφίας του τμήματος Γεωλογίας του Πανεπιστημίου Πατρών, η οποία ξαναπιάνει το νήμα των ερευνών από τους H. Edgerton, P. Throckmorton και Χ. Κριτζά αναζητώντας την αρχαία Ελίκη (Ferentinos et al 2015;Theodoulou 2015, 86). Το 1996 το ίδιο εργαστήριο διεξήγαγε έρευνα στον κόλπο του Ναυαρίνου (Papatheodorou et al 2005;Theodoulou 2015, 88).…”