Comment on “Coastal subsidence, destruction layers and earthquakes from an underwater archaeological excavation: Kenchreai, eastern harbour of Roman Corinth, Greece” by S. C. Stiros. Mediterranean Geoscience Reviews, https://doi.org/10.1007/s42990-020-00019-4

The paper by Stiros (2020) suggests a coastal subsidence of about 1 m caused by a destructive earthquake that hit Kenchreai ca. 400 AD, suggesting as causative faults for this seismic event either Kenchreai or Sofiko faults. In the absence of field observations and underwater survey results, the author attempts to reconstruct the relative sea level (rsl) history of the area and bases it on global rsl data from the Tyrrhenian Sea and NW Mediterranean, a comparatively stable tectonic area (Lambeck et al. 2004) without major seismic activity for the past 2000 years (Boschi, et al. 1997; Guidoboni 1989; Guidoboni et al. 1994), adopting rough estimates on former sea level stands for long former periods, and on two uncertain assumptions. First, he accepts the operational depth of 1.60 m below mean sea level for a structure with its use in question (“piscinae”) thus adopting a fossil mean sea level of 1.60 m. The suggested depth was deduced from the archaeological interpretation, made some 42 years ago (Shaw 1978), of the structure as fish tanks. Second, he accepts a minimum foundation level of 0.80 m for the Sanctuary of Isis. Both assumptions are open to question, as we explain below. However, the author uses these numbers to extract a tectonic subsidence of 1.10 m for the last 2000 years. We have the opportunity offered by Stiros (2020) to reinforce our opinion that the suggested fossil mean sea level of 1.60 m for Kenchreai is not consistent with geomorphological and archaeological sea level indicators recorded in Kenchreai Bay and the submerged structure in Kenchreai interpreted as “fish tanks (piscinae)” could not have served as such.