Comparison of three Andean volcanic complexes through Multidimensional Analyses of geomorphometric data

The geomorphometric classifications of local topographic gradients for three volcanoes situated in the Andes Cordillera, Parinacota, Socompa, and Tata Sabaya, are introduced and compared.. Input data are eight topographic l gradients obtained by processing raster Digital Elevation Models extracted from ASTER stereo-pairs. Based on these data, the pixels have been classified through a clustering procedure applied to coordinates resulting from Principal Component Analysis. The resulting thematic colour maps show the spatial distribution of homogeneous landform units, highlighting the impact of erosional and tectonic processes on the whole reliefs. Moreover, each class is described by both mean gradient values and mean topographic attributes such as elevation, slope and aspect. An unexpected result concerns the high similarity among the three volcanoes concerning the classes of pixels oriented toward SE, S, and SW: this suggests some common trigger phenomenon.