Comment on "On the cause of the 1908 Messina tsunami, southern Italy" by Andrea Billi et al

Introduction: [1] The December 28th 1908 Messina Earthquake has been ranked as one of the most destructive events of the last centuries [Davison, 1936] The damages produced by ground shaking were aggravated by the effects of a remarkable tsunami, with up to 11 m of run-up height, that followed the earthquake [Omori, 1909; Baratta, 1910; Tinti et al., 2004]. The location of the causative fault is still a matter of debate [e.g., Argnani et al., 2009], the modelling of the associated tsunami [Tinti and Armigliato, 2003] allowing uncertainty. [2] Billi et al. [2008] have recently proposed that the tsunami that stroke the coast of the Strait in December 1908 originated from a large submarine landslide (20 km3) located offshore Giardini-Naxos. The hypothesis is based on the study of tsunami arrival times [Platania, 1909; Baratta, 1910] and is supported, according to Billi et al. [2008], by inspection of: a multibeam morphobathymetry [Marani et al., 2004] and of a crustal-scale seismic profile [Scrocca et al., 2004]. [3] The arguments of Billi et al. [2008], however, have weak points that cast doubt on their interpretation. But most importantly, data collected in the last few years by the authors of this comment (A. Argnani and F. Chiocci), and work on tsunami modelling (S. Tinti and his group) cast further doubt on the proposed hypothesis that a large submarine landslide that was caused by the 1908 earthquake is located offshore Giardini-Naxos. These issues will be discussed in the following.