Rock glacier permafrost in the Central Andes of Argentina (PermArg): regional distribution - ice content - hydrological significance

• Applicant: Professor Dr. Lothar Schrott
• Subject Area: Physical Geography
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282220719

Rock glaciers are the predominant periglacial landform in the Central Andes. Within the permafrost body and the seasonally frozen active layer, rock glaciers potentially store large amounts of water. As opposed to ice glaciers, it remains largely unclear how the dynamics of these water reservoirs affect the hydrology of these regions. Due to their large abundance in this part of the Andes, the hydrological significance of rock glaciers has triggered a strong scientific debate. Therefore local studies assessing water storage capacities of rock glaciers are urgently needed The Central Andes of Argentina between 30 and 33°S represent an ideal location to close this research gap, because the study area features probably the highest rock glacier concentration in the world, the agriculture critically depends on melt water, and Morenas Coloradas and Dos Lenguas rock glaciers have been subject of previous permafrost investigations. The aims of the proposed research project are (i) to determine how climate, topography and lithology control the spatial distribution of rock glaciers in the Central Andes of Argentina between 30 and 33°S; (ii) to quantify seasonally stored and released water equivalents from active layer sediments as well as ice contents of permafrost bodies in two local rock glaciers; and (iii) to estimate water storage capacities of rock glacier permafrost in the whole study area. To achieve these objectives we will use a combination of field geophysics (electrical resistivity tomography (ERT), refraction seismic tomography (RST), ground penetrating radar (GPR)) and four phase modeling to estimate the volumetric ice contents of the active layer and the permafrost bodies of the Morenas Coloradas and Dos Lenguas rock glaciers. Local investigations will be complemented by direct observations of sediment properties, thermal monitoring and field based mapping. Regional controls of the rock glacier distribution will be investigated by compiling and analyzing a remote sensing based inventory that further serves as basis for a first order quantification of the water storage capacities of rock glaciers based on empirical field data. This enables us to draw quantitative conclusions on the hydrological significance of Andean rock glacier permafrost.

• DFG Programme: Research Grants