Multidisciplinary Approach to Rainfall-Triggered Rockfalls: the Case Study of the Disaster of the Ancient Hydrothermal Sclafani Spa (Madonie Mts., Northern-Central Sicily, Italy) in 1851

In 1851, the region of Sicily experienced many rainstorm-induced landslides. On 13 March 1851, a rainstorm brought about a severe rockfall disaster near the small town of Sclafani (Madonie Mountains, northern-central Sicily, Italy). Rocks detached from the carbonate crest of Mt. Sclafani (813 m above sea level) fell downslope, causing the collapse of the ancient hydrothermal spa (about 430 m above sea level) and burying it under their fragments. Fortunately, the event did not cause injuries or victims. Given its geological, geomorphological and structural features, the calcareous-dolomitic and carbonate-siliciclastic relief of Mt. Sclafani is extremely prone to landsliding. This study combines the findings from detailed geological and geomorphological field surveys and from a critical review of documentary data. A thorough analysis of documentary sources and historical maps made it possible to identify the location (previously unknown) of the ancient spa. The rockfall dynamics was traced back by comparing field reconnaissance data and documentary sources. The reconstruction of the 1851 event can help gain greater insight into the rockfall susceptibility of Mt. Sclafani, improve future land-use planning, safeguard thermal springs, and reduce the occurrence of similar disasters in this area.