Contribution of Landsat synthetic stereopair to morphotectonic analysis in the Irpinia area (southern Italy)

Abstract

Satellite image analysis has been extensively used in structural geology applications, mainly for the detection of small scale geological structures by means of their morphological evidence. In order to improve the detection of surficial geological structures and to allow the interpreter to frame each observable landform into a regional morphotectonic and structural evolution model, a suitable processing was applied to the digital spectral data. A synthetic stereo pair of a single nadiral Landsat image was created to allow stereoscopic viewing, thus integrating the spectral information resulting from satellite imagery with the morphological one, as in classical aerial photo interpretation. This goal has been achieved by introducing a user-defined parallax in the pixel position of the Landsat TM bands, based on elevations from an accurate raster Digital Elevation Model. An application of this procedure is presented for the area affected by the 1980 Irpinia earthquake (Southern Italy). The geo-structural photointerpretation of the created stereo False Colour Composites has yielded much more morphotectonic information than the single nadiral image; subsequent integration with geological and geomorphological data from large scale aerial photographs resulted in the definition of the geometrical relationships between the structural units detected. An interpretative model for the Quaternary morphostructural evolution of the area is presented.