GLOF modelling of Torre Lake and its potential impact in El Chaltén, Santa Cruz, Argentina: Preliminary results

Abstract

The northern slope of the Cerro Solo, located in Southern Patagonian Andes, has a significant instability which could trigger a sudden release of large amounts of water contained in the Torre proglacial lake (Glacial Lake Outburst Flood, GLOF). Such events are highly complex phenomena, with diverse origins and often catastrophic consequences. This paper examines the potential for a rapid increase in the water level caused by a sudden landslide into the Torre Lake, which could lead to an overflow. The subsequent release of water could flood the Fitz Roy River, with the potential to produce damage downstream in El Chaltén locality and its surroundings, affecting inhabitants and tourists visiting the area.In this study, various empirical methods for predicting landslide-generated impulse waves are compared. These methods are then applied to model the potential GLOF. The advantages and disadvantages of this procedure are analyzed and discussed. Based on the estimation of peak discharges of lake outflow using empirical formulas, a two-dimensional (2D) hydrodynamic model was implemented to simulate two potential outburst scenarios, with estimated peak discharges of 1166 m3/s and 1769 m3/s. The possible inundation extent and its impact were assessed based on the depth of water and the flow velocity. This study is a preliminary step toward understanding the magnitude of a potential future GLOF event and what elements that could be affected in order to develop an effective response to minimize impact.