The 1908 Messina Straits Earthquake: Cornerstones and the Need to Step Forward

The Mw 7.1 earthquake that on 28 December 1908 struck the cities of Messina and Reggio Calabria, facing each other across the Messina Straits, was one of the most destructive events of the past century and one of the deadliest earthquakes in human history, causing a huge death toll, estimated from 60,000 to >100,000 (Bertolaso et al., 2008). None of the large earthquakes that occurred in Europe in the twentieth century, some of them with larger magnitudes (Grünthal and Wahlström, 2012), resulted to be as deadly as the Messina earthquake, which sparked a wave of solidarity and grief throughout Italy and worldwide, with the launch of international relief efforts. The earthquake was soon followed by large tsunami waves that swept the coast of eastern Sicily, reaching as far south as the island of Malta, causing about 2000 casualties (e.g., Schambach et al., 2020). The very early observations of Fusakichi Omori, who visited the devastated lands two months after the earthquake, suggested an offshore source for both the earthquake and tsunami (Omori, 1909; Valensise, 2019). Over the years, many scientists have tried to identify the fault that originated the 1908 Messina Straits earthquake. The analyses accomplished so far identified some important constraints for the causative fault, but no comprehensive source model has been presented yet, and no general consensus has been reached. Here, we briefly review some of the proposed interpretations of the 1908 Messina fault, commenting on their reliability, and suggest that looking for a different approach is advisable. Besides scientific interest and the importance for hazard assessment, understanding the origin of the 1908 Messina Straits earthquake has also relevance for the project of a bridge crossing the Straits, which has long been considered. The bridge project has its roots back even before the 1908 earthquake, but since the 1970s, this issue has been cyclically discussed in political propaganda during (far too many) election campaigns, in those occasions being considered a necessary infrastructure project.