INTERNAL STRUCTURE OF A LARGE, COMPLEX ROCK GLACIER AND ITS SIGNIFICANCE IN HYDROLOGICAL AND DYNAMIC BEHAVIOR. A CASE STUDY IN THE SEMIARID ANDES OF ARGENTINA

CRISTIAN VILLARROEL; AGOSTINA ORTIZ; ANA PAULA FORTE; TAMBURINI BELIVEAU, GUILLERMO; DAVID PONCE; ARMANDO IMHOF; LÓPEZ HIDALGO ANDRES

PERMAFROST AND PERIGLACIAL PROCESSES

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2021

1045-6740

This paper presents the analysis of the internal structure, hydrogeology and dynamics of a large-sized, complex, multi-lobate and multi-root rock glacier combining electrical resistivity tomography (ERT), hydrochemical data and Differential Interferometry Synthetic Aperture Radar (DInSAR). Said rock glacier consists of a series of overlapping lobes that represent different advancing stages with different degrees of conservation. The ERT surveys characterize the active layer and the upper part of the permafrost layer, the latter showing a heterogeneous geometry and electrical resistivity values ranging from 7 to 142 kΩm. Hydrochemical data argue for both the existence of different disconnected water flow pathways inside the rock glacier and the remarkable ionic concentrator effect of this landform. The horizontal displacement from October 2014 to April 2017 exhibits its greatest magnitudes in the upper sector of both tongues, reaching speeds of up to 150 cm/year. The active frontal sector shows a displacement rate of 2 to 4.5 cm/year. This study contributes to the knowledge of the material properties of rock glaciers, which are considered to represent important reservoirs/water resources, and their influence on the distribution of mountain permafrost, hydrology and dynamics. Finally, to the best of our knowledge, the possible influence of the metal content of the ground on the resistivity values recorded for mountain permafrost is highlighted for the first time.