The enigmatic 1693 AD tsunami in the eastern Mediterranean Sea: new insights on the triggering mechanisms and propagation dynamics

Abstract

The disastrous earthquake of 1693 AD caused over 60,000 causalities and the total destruction of several villages and towns in south-eastern Sicily. Immediately after the earthquake, a tsunami struck the Ionian coasts of Sicily and the Messina Strait and was probably recorded even in the Aeolian Islands and Malta. Over the last few decades, the event has been much debated regarding the location of the seismogenic source and the possible cause of the associated tsunami. The marine event has been related to both a submarine landslide and a coseismic displacement at the seafloor. To better define the most reliable sources and dynamics of the tsunami, we couple high-resolution marine seismic survey data with hydrodynamic modelling to simulate various scenarios of tsunami generation and propagation. Results from the simulations are compared with geomorphological evidence of past tsunami impacts, described in previous work along the coast of south-eastern Sicily, and within historical chronicles and reports. The most reliable scenario considers the 1693 event composed by two different tsunami waves: a first wave generated by the coseismic fault displacement at the seafloor and a second wave generated by a submarine landslide, triggered by the earthquake shaking. Tsunami modelling shows that a simultaneous movement between fault displacement and submarine mass movement could determine a destructive interference on the tsunami waves, resulting in a reduction in wave height. For this reason, the second tsunami wave probably occurred with a maximum delay of few minutes after the one generated by the earthquake and induced a greater flooding. The double-source model could explain the observation because in the course of other destructive earthquakes in south-eastern Sicily, such as that of 1169 AD, the associated tsunami caused less damages. This implies the need to better map, define and assess the hazard responsible for this type of tsunami events.

Ionospheric Total Electron Content (TEC) Anomalies as Earthquake Precursors: Unveiling the Geophysical Connection Leading to the 2023 Moroccan 6.8 Mw Earthquake

“…It is noteworthy not only for its high casualty count, approximately 60,000 lives lost, but also for generating a tsunami that surged along the Portuguese coast, inundating coastal settlements and Lisbon [36]. Similarly, in 1693, an earthquake of around M7.4 near Sicily produced a substantial tsunami wave that devastated numerous towns along Sicily's eastern coastline [37]. Europe's deadliest documented earthquake, the M7.2 28 December 1908 Messina earthquake, resulted in an estimated 60,000 to 120,000 fatalities due to the combination of intense ground shaking and a local tsunami [38].…”

Interseismic and long-term deformation of southeastern Sicily driven by the Ionian slab roll-back

“…Geodetic measurements, instrumental seismicity, onshore/offshore geology, and geophysics, all indicate that Southeastern Sicily is actively deforming (e.g., Anzidei et al, 2021;Azzaro and Barbano, 2000;Mastrolembo et al, 2014;Meschis et al, 2020). This region also suffered the most powerful and devastating earthquake reported in the Italian seismicity catalog, the 1693 Mw~7.4 Val-di-Noto earthquake, which occurred along the eastern margin of the Hyblean Plateau (e.g., Bianca et al, 1999;Billi et al, 2010;Gutscher et al, 2006;Scicchitano et al, 2022). The current geologic and tectonic framework is in line with the Cenozoic geodynamic evolution of the Central Mediterranean (Figure 1), but also appears to be influenced by the Mesozoic pre-structuration of this region (e.g., Carminati and Doglioni, 2005;Frizon de Lamotte et al, 2011;Henriquet et al, 2020;Van Hinsbergen et al, 2020).…”

Long‐term drivers of shoreline change over two centuries on a headland‐embayment beach

“…Wave direction and energy are also influenced by geological constraints such rocky headlands which affect wave shoaling and shoreline response to storms in headland embayed beaches (Daly et al, 2014; Gallop et al, 2020). Over a long period of time, an important contribution to shoreline change is possible through by the occurrence of tsunami events where these events can be a significant factor in modifying the coastline (Scicchitano et al, 2022).…”