Earthquake-induced ground failure in Central and Southern Italy

A large portion of Italy is located in a high‐seismicity area. This results in high seismic hazard that, combined with a high vulnerability of Italy’s territory to slope instability phenomena, produces a high earthquake‐induced landslide risk. Furthermore, the Italian territory is also characterized by other ground failure and/or geotechnical issues including earthquake‐induced liquefaction and surface fault rupture. Such phenomena were abundantly observed in recent strong earthquakes such as the 2012 Emilia and 2016 Central Italy events. This paper focuses on earthquake‐induced landslides (i.e., coseismic landslides) in Central and and Southern Italy. A total of 11 earthquakes were considered, with a temporal span ranging between 1783 and 2016. The magnitude range of such earthquakes is 5.9‐7.1. Some of these earthquakes are part of earthquake sequences. In this study two main sequences were analyzed: (1) the 1783 events in Calabria (Southern Italy), and (2) the 2016 events in Central Italy. Only earthquake events for which landslide catalogues were considered complete and reliable were included in the dataset. The analysis presented in this paper focuses on two parameters often used to evaluate earthquake‐induced effects on a regional scale: (1) the total area within which coseismic landslides are located, and (2) the maximum source‐to‐site distance of earthquake‐induced landslides for each event. For both parameters it is possible to obtain limiting curves as a function of magnitude. Both parameters were calculated for all considered events and compared against existing empirical limiting curves calibrated on global datasets. The majority of analyzed earthquakes are within the ranges of existing empirical curves.