Origins of the Tsunami Following the 2023 Turkey-Syria Earthquake

On 6 February 2023, a local tsunami was recorded in the southeastern Mediterranean Sea following the Mw 7.7 Turkey-Syria inland strike-slip earthquake. Due to the lack of underwater observation, the tsunami generation mechanism remains mysterious. To understand the source mechanisms, we analyzed the tsunami waveforms of four nearby tide gauges and located possible sources using a backward tsunami ray tracing approach. We then conducted forward numerical modelings for a range of possible source parameters. We show that there were probably two tsunami sources, inside and outside Iskenderun Bay, which may be related to thick coastal sediments. A source inside the Bay with a characteristic length of 7 km produced dominant periods of 10-30 min with negative initial motion, possibly generated by a landslide. Another source of 6 km length outside the Bay produced dominant periods of 2-10 min with positive initial motions, possibly related with liquefaction. Inland earthquakes, especially inland strike-slip earthquakes rarely produce tsunamis since tsunami waves are normally generated by vertical displacements accompanied with fault ruptures. On 6 February 2023, the Turkey-Syria strike-slip inland earthquake of Mw 7.7 mysteriously generated a small-scale tsunami in the southeastern Mediterranean Sea. Due to the complexity of the earthquake source and lack of underwater observation, how the tsunami waves were generated remains mysterious. To understand the tsunami origins, we analyzed the tsunami waveforms in different aspects and adopted numerical modelings to explore the possible sources. We find that there existed two tsunami sources probably generated by landslides inside the Iskenderun Bay and related with liquefactions outside the Bay. We therefore highlight the potential threat caused by the disaster chain of coastal strike-slip earthquakes. We find distinctly different tsunami wave properties inside and outside the Iskenderun BayWe obtain possible tsunami sources that can well explain the observed tsunami waveformsUnderestimated and unpredictable tsunami origins due to the disaster chain caused by coastal strike-slip earthquakes call for more attention