Current landslide-dammed lakes in the Central Andes of Argentina (31º - 36º S).

CORREAS GONZALEZ M.; MORERIAS S.M.; JEANNERET P.

Revista de la Asociación Geológica Argentina

Asociación Geológica Argentina

Año: 2023 vol. 80 p. 317 - 333

1853-7138

In many regions around the world, landslide dammed lakes are a common feature. Assessing the stability of these lakes is crucial when communities and infrastructures are exposed to the hazard related to the potential collapse of these dams, a phenomenon known as Landslide Lake Outburst Floods (LLOF). In this paper, we study systematically current landslide-dammed lakes in the Central Andes of Argentina to characterize the lakes, the natural dams, and the outburst flood record. Moreover, we analyze dam stability through classical geomorphic indexes and by a qualitative assessment of the apparent stability of the dams, which depends on both the inner features of the dam and the site conditions. We identified 19 landslides currently damming lakes that correspond to historical dams as well as palaeo-dams. We observed that current lakes might be long-lasting and considered stable by the classical indexes and nevertheless constitute sources of potential LLOFs. In the study area, lake destabilizing factors could be related to extreme climatic conditions or to seismicity, yet the stability indexes used do not consider these factors. Evidently, LLOF occurrence in historical times, as well as paleo-LLOFs, suggest that this type of flooding is a common phenomenon in the study area, indicating the need for continuous monitoring since the apparent stability of the dams might be disturbed by external factors.