The origin of the tsunami of 6 February 2023 in the north-eastern Mediterranean

An earthquake of Mw=7.8 occurred on 6 February 2023 along the North East – South West trending East Anatolian Fault (EAF) in southern Turkey bordering Syria. It triggered in about 9 hours a Mw=7.5 earthquake on the Sürgü Fault (SF). The first event was followed by a weak tsunami that was observed on few coastal tide gauges in the north-eastern Mediterranean, reaching maximum amplitudes in the order of 25 cm. In this thesis, two generation mechanisms are considered: the first involves the activation of an offshore tectonic source, while the second considers a submarine landslide. A number of hypotheses about the source is tested employing JAGURS, a numerical code that computes tsunami propagation and inundation on the basis of the long wave approximation, allowing also to account for dispersive effects. Thanks to JAGURS it is possible to compare the simulations’ outputs, in particular the waves’ amplitude, with the observations available, provided by the tide gauge stations of Gazimagusa/Famagosta(Cyprus), Arsuz(Turkey), Erdemli(Turkey) and Tasucu(Turkey). The goal of the comparison is to put reasonable constraints on the nature and the characteristics of the source of the observed tsunami. The inversion of the tide gauge data, due to multiple approximations and limitations, did not allow to put any satisfactory constraint on the on-fault heterogeneous slip distribution for any of the examined tectonic sources. On the other hand, the signals obtained using a highly simplified landslide model allow for the identification of a source area off the coast of Hatay Province, where it is possible to reproduce the main characteristics of the observed tide gauge records in the first minutes following the tsunami's arrival. In one case, the reproduction closely matched what was observed at a single station, leading to the hypothesis of the combined action of a submarine landslide with sources of different nature.