Quantitative analysis of InSAR Digital Elevation Models for identification of areas with different tectonic activity in southern Italy

摘要

This work presents the results of a quantitative analysis of an interferometric SAR (InSAR) digital elevation model (DEM), obtained by the Shuttle Radar Topography Mission (SRTM). The analysis aims to identify additional parameters to recognize areas in southern Italy with different tectonic activities and behaviours. The axial zone of the Campania-Lucania Apennine and the Sila Massif in Calabria, Italy, characterized by quite different evolutionary histories, have been chosen as test areas sufficiently wide to validate observations on a sub-regional scale at least. Geomorphological information on the shape of palaeosurfaces has been used to estimate uplift and/or erosion amounts and rates. Palaeosurfaces are identified on the DEM as regions with an altitude higher than 1000 m a.s.l. and sub-planar land surfaces dipping less than 6°. Information about the shape of palaeosurfaces during the first stage of uplift and before the tectonic-induced block fragmentation has been extracted. A fragmentation index has been computed for these erosional surfaces. The first stage of this landscape evolution has been studied in terms of the geometric characteristics of fragmented blocks. The last erosional stage has been recognized in terms of both geometric characteristics and fragmentation index of the sub-horizontal land surfaces. Altitude and age of the palaeosurfaces, referred to ancient base-levels of the erosion, have been used to estimate the erosional rate.