Abstract
September 1997 registered the onset of a seismic sequence striking the Umbria-Marche region (Central Italy), in which earthquakes up to intensity IX caused widespread damage. With respect to villages settled in an intermountain basin near the epicentral area, the resulting damage pattern is investigated to give a better understanding of future local ground-motion sensitivity. Macroseismic data are collected and compared with the surface geology of 26 villages and hamlets within a restricted area. Among these 26 settlements, seven individual groups of different geological conditions are discernible, showing a gradual variation to the damage severity. The greatest damage occurred within the basin, in villages settled close to border faults. Significant damage also occurred at locations on the contact between fan debris with bedrock or alluvium. In support of models existing in literature, these observations show that strong shaking can be generated at the edge of basins.