Father Serpieri, a forerunner of earthquake observation: from the “seismic radiant” to twenty-first century analyses

Father Serpieri was certainly one of the pioneers of modern seismology, also because at least two strong earthquakes occurred in the region of central Italy where he lived during his mature age: in southern Marche in 1873, and near Rimini in 1875. Serpieri was interested in the investigation of earthquake location and had already established that every earthquake originates from a “seismic radiant”. Unfortunately, the 1873 earthquake was a tricky one: both because—unbeknown to him—the earthquake records he managed to collect from over 100 observatories were very imprecise in terms of time reference, and because that earthquake was substantially deeper than average upper crustal earthquakes, hence more difficult to relate to physiographic and shallow-rooted geological features. Notwithstanding these drawbacks, Father Serpieri’s research was an important step in understanding the cause-effect relationships between the large faults, which had not yet been imagined and understood in their essence, and the strong earthquakes they generated. The depth of his intuitions compensated the inaccuracy of his elaborations of instrumental data: Father Serpieri became a solid reference for the seismologists who contributed to the success of Italian Seismology between the end of the nineteenth and the beginning of the twentieth century.