Abstract ID: 3.11052 | Accepted as Talk | Talk/Oral | TBA | TBA

Nowadays, glacier-related mass movements are increasingly known globally. These include rock and ice avalanches, catastrophic detachments, glacier surging, lahars and GLOFs. Although the conditioning and triggering factors of these phenomena are multiple and diverse, rock glaciers are usually excluded as the source of these mass movement processes. Rock glacier instabilities comprise abnormal acceleration phases, the development of fractures and crevasses, and even the partial or total collapse of the whole ice mass. The existence or absence of a link between these instabilities and climate change is a matter of ongoing research. This contribution highlights multiple unreported case studies in the Central Chilean Andes. First, three debris-flow events originating from rock glacier’s front in the last decade are shown: CL105721033 (-33,173/-70,291), Metropolitan Region (RM), CL105400105 (-33,010/-70,083) and CL105400002 (-32,867/-70,112), Region of Valparaiso. A link to Zonal Atmospheric Rivers, acting as triggering factors, is discussed. Secondly, the anomalous advance of two rock glaciers located in the Metropolitan Region is analysed: CL105703065 (-33,580/-69,874), also known as “Rocoso Pirámide”, and the glacier CL105720032 (-33,308/-70,258), referred to as “Ballicas Norte”. In both cases, chaotic fractures are shared with steep and pronounced scarps at the rock glaciers’ front and abnormal advancing rates around 1.4 m per year since 1955 and 2004 for the Rocoso Pirámide and Ballicas Norte rock glaciers, respectively. In all cases, a high percentage of ice within the rock glacier is inferred as a conditioning factor for developing such instabilities. This is supported by the outcropped ice observed in the aftermath of every debris flow and by the pre-advancing behaviour of the Rocoso Pirámide and Ballicas Norte rock glaciers, according to remote-sensed data. We conclude that these phenomena are more common than thought. Thus, special attention should be given to the proximity of rock glaciers to large mining and industrial prospects in the Central Andes of Chile.