Increasing risks related to landslides from degrading permafrost into new lakes in de-glaciating mountain ranges

Morphological analysis and features of the landslide dams in the Cordillera Blanca, Peru

“…In general, dammed lakes in high mountain areas pose hazards because (1) the surrounding environment is characterized by very high relief energy, which produces highly destructive floods/debris flows; (2) they are downslope from glaciers and steep unstable rock slopes, susceptible to slope movements (e.g., Haeberli et al 2016); (3) small debris flows from the steep valley sides constantly supply new material to fall on the dam body, resulting in a precarious balance of the repeatedly Brejuvenated^dam; and (4) the vegetation is not able to stabilize their slopes due to the high elevation and the rapid rate of geomorphic change on the dam body (Costa and Schuster 1988).…”

Compiling an Inventory of Glacier-Bed Overdeepenings and Potential New Lakes in De-Glaciating Areas of the Peruvian Andes: Approach, First Results, and Perspectives for Adaptation to Climate Change

“…Maximum depth and volume of the future lake at this flat glacier tongue as calculated using GlapTop are 58 m and 4.45 million m 3 . Best estimates from inter-and extrapolated radio-echo soundings (about 10 predominantly parallel longitudinal profiles) provide corresponding values of 80 m and about 10 (4.5 to 17.3) million m 3 . This confirms that ice-depth estimates using GlabTop are within about ±30% of real ice thicknesses [5].…”

“…With regards to the timing of possible lake formation, in regions with a high density of quantitative glacier information such as the European Alps, spatially distributed model simulations can be used to estimate realistic time sequences of glacier retreat followed by the formation of possible new lakes in glacier-bed overdeepenings, which become exposed through glacier retreat or even vanishing [3,35]. The density of information in the Cordilleras of Peru, however, is low, especially concerning the upper parts of the still existing glaciers.…”

“…The latter are interesting for tourism, hydropower production, and water supplies [2]. They can, however, also be amplifiers of hazards and risks, especially in connection with impact/flood waves triggered by rock/ice avalanches from glacially de-buttressed slopes and slowly destabilizing icy peaks [3,4]. With digital terrain information having become available at increasingly high-resolution, slope/flux-related approaches for estimating Initial lake formation at Glaciar Artesonraju, Cordillera Blanca.…”

Observation-Based Estimates of Global Glacier Mass Change and Its Contribution to Sea-Level Change

“…Because of these properties, glaciers have become one of the key indicators of climate change (e.g., WGMS 2008; Marzeion et al 2014a). Perhaps more importantly, glaciers are closely linked to the Earth system not only by being shaped by atmospheric conditions and their topographic setting, but by changing the seasonality of water runoff in many large river systems (e.g., Immerzeel et al 2010;Kaser et al 2010;Huss 2011), by being central to many geomorphologic processes (e.g., Egholm et al 2009;Korup et al 2010; Thomson et al 2010;Koppes et al 2015;Haeberli et al 2016) and by affecting sea level through changes of the terrestrially stored water mass (see e.g., Radić and Hock 2010;Huss and Farinotti 2012;Grinsted 2013 for current estimates of mass stored in glaciers). Of interest here are changes to the mass of water stored in glaciers on the global scale, thus affecting the global mean sea level, over a time scale of several years (i.e., excluding seasonal mass changes, Jansson et al 2003).…”