Capable faulting, environmental effects and seismic landscape in the area affected by the 1997 Umbria–Marche (Central Italy) seismic sequence

The September–October 1997 seismic sequence in the Umbria–Marche regions of Central Italy has been one of the best studied from the seismological, macroseismic and geological point of view. Numerous papers have been published in the period immediately after the seismic sequence, providing a significant database of effects triggered by the earthquake on natural environment. In the following years, further studies have provided additional pieces of evidence that allow to better relate the seismic sequence with its geological background. Moreover, recent developments in the characterization of coseismic environmental effects provide new horizons in seismic hazard assessment (SHA) procedures, which should take into account even long term geomorphological and geological features resulting from repeated characteristic earthquakes (concept of “seismic landscape”). This paper reviews the current state of knowledge on the 1997 Umbria–Marche seismic sequence, with particular regard to coseismic environmental effects (primary and secondary), that have been used for ESI seismic intensity assessment, in order to verify if i) they are consistent with geological, seismological and macroseismic data in the location and characterization of the seismogenic structure, and ii) if they fit the “seismic landscape” features that mark the epicentral area of Colfiorito.