Tsu-Memo: 11 January 1693, the Val di Noto tsunami in eastern Sicily

Two strong earthquakes, the first on 9 January and the second on 11 January, struck eastern Sicily. In particular, the second event was the strongest and most catastrophic earthquake in Italy in the last 1,000 years (Parametric Catalogue of Italian Earthquakes CPTI15) and generated a tsunami well described by contemporary chroniclers.

This event, also known as the Val di Noto earthquake, is remembered not only for its immediate consequences in terms of human and material losses, but also for the lasting impact it had on the history, town planning and culture of south-eastern Sicily. The entire south-eastern part of the island, in fact, experienced socio-demographic and cultural changes caused by what was defined as one of the worst disasters to strike Europe in the modern age (an article published on INGVTerremoti - in ITA - discusses this aspect in more detail).

The major quake, which occurred on 11 January 1693 at 13:30 GMT, was felt in a wide area of southern Italy. Contemporary sources tell of oscillations caused by the strong earthquake felt as far as Malta, parts of Calabria and Naples. The greatest number of casualties and damages were recorded between the province of Catania and Syracuse, as far inland as the Vallo di Noto (official statistics, compiled in May 1693, report about 54,000 deaths).

In addition to the losses caused by the earthquake, the effects generated by the tsunami were devastating. Historical sources extensively describe the initial retreat of the sea, a phenomenon that we now recognise as a premonitory sign of a tsunami (this phenomenon does not always occur: in some cases, the tsunami may begin with a ‘positive’ wave that directly hits the coast without a previous retreat of the sea).

In the Euro-Mediterranean tsunami catalogue, the following observations are detailed.

The city of Augusta (SR), at the time a prosperous commercial harbour and crossroads for the trade of products from the Middle East, was among the worst affected.
The first effect observed there was the retreat of the sea. The phenomenon completely dried up the harbour, causing severe damage to the ships moored there, in particular to two large Maltese vessels that crashed hard into the harbour bed. The flooding that followed the sea receding, submerged the neighbourhood adjacent to the port, up to the church of St. Domenico, about 150m from the sea (Acquaviva, 1693; Boccone, 1697a, b, c; Mongitore, 1743; Anonimo, 1693d; Burgos, 1693; Muglielgini, 1695). Many casualities were caused by the tsunami, especially women and children who, frightened by the tremors felt in the previous days, found refuge by camping near the quay (Anonimo, 1693e). In Augusta, run-ups of around 15m were observed.

A considerable sea level rise was observed in Catania (Burgos, 1693) followed by the retreat of many boats (Campis, 1980; Anonymous, 1693a, b). For about 15 minutes, a sequence of waves was observed, three of which reached the city walls. The sea water flooded the city as far as Piazza San Filippo; farms located near the city were inundated (Boccone, 1697a).

According to Boccone (1697a), three retreats and floods were observed in Syracuse. The harbour remained dry for more than 50 paces (more than 70 metres) making the seabed visible; the subsequent waves reached heights of more than 8 feet (run-up of about 2.5 m) above the usual level. The fishermen, who usually cast their nets at a depth of 15 ‘rope steps’, were surprised that for about 15 days the nets reached the seabed with only 5 rope steps.

In Messina, near the Citadel fortress, three retreats and returns of the sea were observed (Anonymous, 1693a): the sea retreated 60 paces (about 50 m) and then strongly returned as it passed the pier's dock. Many fish were found on the beach (Boccone, 1697a).

At Mascali the sea submerged the shore for about 1 mile (about 1.5 km) inland (Boccone, 1697a).

At Taormina (Giardini Naxos) the sea receded for about half a mile dragging some small boats (Boccone, 1697a).

At Mazzarelli (today Marina di Ragusa) the sea receded and then strongly returned causing damage to a moored boat (Guidoboni et al., 2018).

On the island of Lipari, the sea was very rough and flooded the beach (Guidoboni et al., 2018).

In Gozo (Malta archipelago), according to Camilleri (2006), who in turn cites Aguis De Soldanis, the sea at Xlendi receded to about a mile and then turned back shortly afterwards ‘with great rush and murmur’.

Recent interdisciplinary studies combined geological, seismological and historical analyses. Marine sediments taken along the east coast of Sicily reveal unmistakable traces of the 1693 tsunami, confirming the magnitude and extent of the event. Historians, on the other hand, have carefully examined the chronicles of the time, comparing descriptions of the event with modern knowledge about the dynamics of earthquakes and tsunamis.

The combination of studies has made it possible to reconstruct more accurately what happened that day and to assess the overall impact of the event, which radically transformed the physical and cultural landscape of south-eastern Sicily and the Vallo di Noto.