GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 The 1783 Calabria earthquake sequence: a review of the coseismic efects on the natural environment C. Zei 1,2 , C. Ciuccarelli 1 , M.G. Bianchi 1 , G. Tarabusi 1 , D. Mariot 1 1 Isttuto Nazionale di Geofsica e Vulcanologia, Italy 2 Università degli Studi di Ferrara - Dipartmento di Fisica e Scienze della Terra, Italy The primary goal of the inital versions of the CFTI (Boschi et al. 1995, 1997 and 2000) was to defne the efects of strong earthquakes on the built environment. Consequently, the efects on the natural environment (EE) were not extensively studied but were considered as additonal informaton. In recent years, startng from the CFTI5med (Guidoboni et al, 2018 and 2019), special atenton has been devoted to the retrieval and analysis of the EE. Here we present a review of the efects on the natural environment of the 1783 Calabria earthquake sequence, startng from the data already included in the CFTI database. The earthquake sequence began on 5 February 1783 and lasted for over three years, featuring fve main shocks with a magnitude between 5.9 and 7.0 (5 February, 6 February, 7 February, 1 March, and 28 March 1783) and several hundred smaller shocks, which had cumulatve devastatng efects over an area of several thousand square kilometers. Within two months, from 5 February to 28 March, the earthquake actvity migrated from the foothills of the Aspromonte to the area between the Golfo di Sant'Eufemia and the Golfo di Squillace. Before this review, for the 1783 earthquake sequence the CFTI5med reported 222 EE, grouped into 14 diferent categories based on the observed natural phenomena. The most frequently observed typologies were landslides (67 observatons), ground cracks (57 observatons), and water efects (38). Only 2% of the 222 EE were assigned to a specifc earthquake of the sequence. Other recent reviews (Cucci 2022) pointed atenton to specifc types of efects instead, in this work, we collected all the efects on the natural environment reported. We focused on the review of 22 historical sources coeval with the earthquake, already archived in the CFTI5Med. These sources are the most reliable for the sequence, as many such as Vivenzio (1783) and Sarconi (1784), describe the efects on the natural environment afer their survey of the epicentral area. The CFTIvisual dataset (Bianchi et al., 2022) plays a central role in this work as it supplies over thirty historical original drawings that can be used to identfy and locate the EE: indeed, they show