Minor earthquakes in the asolo area (1861-1921)

Abstract

The need to improve hazard assessments with more up-to-date basic data is also supported by the awareness of how important the seismicity of an area is in the perspective of risk assessment. Although the occurrence of strong earthquakes is decisive for these assessments, increasing weight in the latest hazard models is given to information on intermediate and moderate energy earthquakes. This study consists of a comprehensive review of the information available for six 'minor' earthquakes that occurred in the Treviso area close to the Venetian Prealps, in particular the area close to Asolo, in the chronological span of 1861-1921. The area under examination, which from a seismic characterization point of view can be identified as 'Pedemontana Sud' (Sugan and Peruzza, 2011), presents various reasons of interest from many angles: physical, geological (just think of the presence of the Montello massif) and landscape. It is a particularly important industrial and craft district, with a significant economic weight and exposed value, represented by the density of the population and the settlement network. From the preliminary studies available, research was carried out ex novo, going back to the original sources and redetermining the epicentral parameters of each event on a new basis. In particular, the earthquakes taken into consideration are those of 19 May 1861, 14 April 1887, 11 June 1897, 4 March 1900, 12 July 1919, and 12 September 1921, all included in the CPTI15 catalogue (Rovida et al., 2022) based on preliminary studies and therefore not very in-depth. Since this is a work on earthquakes of relatively moderate energy, which occurred in a very specific area and fall within a defined historical period, the problems that the historical study must address are far from irrelevant. Indeed, there is not a lot of information available, making the work of verifying and interpreting the data very complex and affected by considerable uncertainties.