The Sant'Agata Feltria landslide (Marche Region, central Italy): a case of recurrent earthflow evolving from a deep-seated gravitational slope deformation

Analysis of massif fracturing during Deep-Seated Gravitational Slope Deformation by physical and numerical modeling

“…At the toe of the DSGSD, an unrealistic steepness of the slope is generated considering the time scale of those gravitational movements. Such steepness should be in nature compensated by shallow gravitational movements (Bisci et al, 1996). These smaller gravitational movements are however directly linked to precipitation and associated weathering and increased rock mass pore pressure which are not reproduced in our models.…”

“…Indeed, many mass movements occurring at smaller time-and spatial-scale are observed in rock masses already affected by DSGSD (Bisci et al, 1996;Crosta, 1996;Agliardi et al, 2001). However, the link between those mass movements and DSGSD is not well well-constrained (Bisci et al, 1996;Sorriso-Valvo et al, 1999), although the topographical modifications as well as the fractures, inherited and/or generated in a response to the DSGSD, must have a consequent impact. The knowledge of geomorphological evolution and massif fracturing due to DSGSD initiation and evolution is thus of primary importance to predict the locations of smaller mass movements.…”

“…The link between those morpho-structural features and deformation in the mobilized mass is however not well known. Deep deformation is often considered as a creep phenomenon without a well-defined continuous sliding surface (Zischinsky, 1966;Tabor, 1971;Mahr, 1977;Mahr and Nemcok, 1977;Bisci et al, 1996;Kinakin and Stead, 2005). Nevertheless, some authors consider the possibility of well well-defined single or multiple sliding surfaces crossing the whole mountain if the amount of deformation is large enough (Beck, 1968;Radbruch-Hall, 1978;Crosta, 1996).…”

Deep-seated gravitational slope deformations and their influence on consequent mass movements (case studies from the highest part of the Czech Carpathians)

“…With some exceptions, young active landslides developed and are still formed in zones of DSGSDs, which has been described even in other young orogenic parts of the Earth (e.g. Bisci et al 1996). The distribution, structure and genesis of deep-seated slope deformations constitute essential causative parameters of landforms for the assessment and mapping of landslide hazards, even though they do not necessarily represent a direct geomorphological risk owing to the mechanism of their movements.…”

Deep-seated gravitational slope deformations in the highest parts of the Czech Flysch Carpathians: Evolutionary model based on kinematic analysis, electrical imaging and trenching

“…Their evolution is driven by diverse gravitational mechanisms such as sackung (alts. sagging, rock flow - Agliardi et al, 2001Agliardi et al, , 2009aGutiérrez-Santolalla et al, 2005;Hürlimann et al, 2006), lateral spreading (Dramis and Sorriso-Valvo, 1994;Bisci et al, 1996;Esposito et al, 2007), toppling (Bovis, 1982;Nichol et al, 2002) or a combination of several hillslope processes (McCalpin and Irvine, 1995;Bovis and Evans, 1996;Margielewski, 2006a). A question still remains unanswered on whether DSGSDs pose a significant risk as for their transformation into catastrophic rock slope failures.…”