Archaeological evidence of earthquakes in the area of Helike, Achaia, Greece from the Early Bronze Age to Late Antiquity
by
Steven Soter
American Museum of Natural History, Central Park West, New York 10024, USA
Coauthors: Dora Katsonopoulou (The Helike Society, Poste Restante 25 003 Diakopton, Achaia, Greece), Ioannis Koukouvelas (Department of Geology, University of Patras, 265 00 Patras, Greece)

Helike, the principal ancient city on the southwest shore of the Gulf of Corinth, was founded in the Bronze Age and destroyed and submerged by an earthquake and tsunami in 373 BC. The Helike Project began to search for the city in 1988, first with a systematic sonar survey of the seafloor southeast of Aigion. Since 1991 the Project carried out campaigns on the adjacent delta plain using surface surveys, geophysical exploration, extensive bore hole drilling, and trial excavations.

The first excavation, conducted in the Klonis Field in modern Eliki in 1995, brought to light the remains of a large rectangular building of Roman date. Excavation data showed that the building was destroyed by an earthquake in the 5th century AD and was subsequently abandoned.

Excavations continued during 2001 and 2002 in the delta plain between the Selinous and Kerynites Rivers. They provided archaeological evidence for the occurrence of other earthquakes, dating from the Early Bronze Age down to the Late Roman period:

EARLY BRONZE AGE. Excavation of three trenches in the Rizomylos area uncovered the foundations of rectilinear buildings flanking the sides of cobbled roads, in a horizon about 4 m below the surface. The remains belong to a most significant and well-preserved coastal settlement of the Early Bronze Age, the first ever found in Achaea. The sediments covering the Early Helladic horizon contain numerous marine microfauna, showing that the ruins were submerged in the sea for some time. The long walls of one building dip seaward and are abruptly offset by what appears to be a seismic discontinuity. This evidence suggests that the prehistoric settlement (dated to EH IIIA, ca. 2500-2300 BC) may have been destroyed and submerged by an earthquake, as happened to its Classical successor some two thousand years later.

CLASSICAL. Excavation of trenches in the mid-plain of the Eliki-Rizomylos area brought to light the foundations of walls buried at 3 m depth under thick lagoonal deposits. The remaining corner of one building showed one of its walls thrown down in the seaward direction, consistent with destruction by the backwash from a tsunami. Recovered pottery dates the destruction to the first quarter of the 4th century BC. Microfaunal analysis of the strata shows that the submerged site of Classical Helike was covered by an inland lagoon, as first suggested by Katsonopoulou in 1995. This appears to explain the ancient reports that the ruins of Helike were long visible under water.

ROMAN. Excavation of three trenches in Nikolaiika uncovered the remains of an extensive complex of Roman buildings. In the narrow entrance to a large cistern in one of the structures, excavation revealed a crushed human skeleton and under it the skull of a large horned animal, buried under a destruction layer of fallen plaster and tiles. This suggests another earthquake, dated from archaeological evidence to the 4th century AD.

Date received: March 12, 2002