Retrospective Modeling of a Large Paleo-Landslide Related to Deglaciation in the Sierra de Urbión, Cordillera Ibérica, Spain

Abstract

Through a study of glacial geomorphology and retrospective modeling of the stability of the slopes, it has been possible to reconstruct and know the mechanism of the formation of a large landslide induced by the retreat of the glacier corresponding to the Picos de Urbión (Coordillera Ibérica, Spain) during the last glacial cycle. It is a rotational landslide of 150 Mm3 that involved a layer of lutites and clays of the Cameros Basin that outcropped on one of the slopes of the valley, and whose initial geometry was modified by the over-excavation of the glacier tongue, which reached 140 m in height. The breakage occurred when the support of the ice tongue was partially removed. The structural layout and high water table also contributed to the landslide. It is the first time that landslides associated with the deglaciations of the last glacial cycle have been retrospectively modeled, which may be of interest when applied to geomorphological sciences.