Radon distribution as shallow evidence of buried fault geometry in the Fucino plain (Central Italy)

The Fucino plain is characterised by a network of buried and known faults activated during the Avezzano earthquake in 1915. Since radon in soil gas is used as an effective fault tracer, radon anomalies in the eastern sector of the plain has been re- interpreted according to new seismic data and new techniques of geospatial analysis to reconstruct the shallow geometry of these buried and known faults. E-W radon profiles was calculated using the radon distribution map, and the spatial distribution of radon peaks was mapped. Spatial location of the radon peaks highlights eastward sharp deviations along the NW-SE oriented Trasacco, Ortucchio Faults, as well as along the San Benedetto dei Marsi fault that borders the eastern side of the plain. These deviations can be inferred as fractured zones (e.g., relay ramps) or real transfer faults causing moving back of these structures towards the mountain.