A critical overview of the January-February 1703 seismic sequence in central Italy

Historical seismic sequences with multiple mainshocks or strong foreshocks and aftershocks make it difficult to attribute the damage distribution to one earthquake rather than another. As a matter of fact, historical reports often describe the cumulative picture of effects, preventing a correct reconstruction of what happened during the different earthquakes. This paper proposes a review of the catastrophic seismic sequence that hit central Italy starting from January 1703. The sequence is currently quoted in some seismic catalogues with three mainshocks that occurred on 14 and 16 January and 2 February, with magnitudes ranging between 6.0 and 6.9. The aim of this paper is to reconsider the sequence on a chronological basis, trying to reconstruct the impact of each single event, taking into account the damage progression when assigning macroseismic intensity. Through this approach, the earthquakes already quoted in the catalogue are reassessed as faithfully as possible, with a richer framework of knowledge than in the past.