Characterization of active fault scarps from LiDAR data: a case 1 study from Central 2 Apennines (Italy)

Abstract

A high resolution DEM (1 ms spacing) derived from an airborne LiDAR campaign was 11 used in an attempt to characterize the structural and erosive elements of the geometry of the Pettino 12 fault, a seismogenic normal fault in Central Apennines (Italy). Four 90- to 280 m -long fault scarp 13 segments were selected and the surface between the base and the top of the scarps was analyzed 14 through the statistical analysis of the following DEM-derived parameters: altitude, height of the 15 fault scarp, distance along strike, slope and aspect. The results identify slopes of up to 40° in faults 16 lower reaches interpreted as fresh faces, 34° up the faces. The Pettino fault maximum long slipe17 rate (0.6-1.1 mm/yr) was estimated from the scarp heights, which are up to 12 and 19 m in the 18 selected four segments, and the age (ca. 18 ka) of the last glacial erosional phase in the area. The 19 combined analysis of the DEM-derived parameters allow us to (a) define aspects of 3D scarp 20 geometry, (b) decipher its geomorphological significance, and (c) estimate the long-term slip rate.