The July 20, 2017 Mw = 6.6 Bodrum-Kos Earthquake, Southeast Aegean Sea: Contribution of the Tsunami Modeling to the Assessment of the Fault Parameters

The South East Aegean Sea is seismically active with crustal and intermediate-depth earthquakes of magnitude that can exceed the magnitude Mw = 7. On July 20, 2017, a shallow normal faulting Mw = 6.6 earthquake occurred in the Gulf of Gokova, 10 km away from the cities of Kos and Bodrum. A tsunami hit the coasts of Turkey and Kos Island with waves of up to 2 m that damaged several harbors. Based on the field surveys and the tide-gauge records of Bodrum, Syros and Kos harbors, we performed tsunami simulations to constrain the source and analyze the North v/s South-dipping solutions for the fault plane. Depending on the source model, the simulations show different height distributions which provide complementary constrains on the source parameters, helping the characterization of the fault plane. The comparison between our maximum wave heights models and the field data favor the North-dipping fault scenario. When using only the constraint of the Bodrum tide-gauge, our models lead to a source with a 0.7 m fault slip, incompatible with the slip inferred from geodesy. When using the constrain from neighboring coastal wave heights and run-up recovered during field surveys, the best fit is obtained with a 2 m fault slip scenario consistent with the geodetic models. There is a 0.25 m mean difference between observed and synthetic water heights that could be due to the unaccuracy of the bathymetry data.