DInSAR for a Regional Inventory of Active Rock Glaciers in the Dry Andes Mountains of Argentina and Chile with Sentinel-1 Data

Abstract

The Dry Andes region of Argentina and Chile is characterized by a highly developed periglacial environment. In these arid or semi-arid regions, rock glaciers represent one of the main pieces of evidence of mountain creeping permafrost and water reserves in a solid state. However, their distribution, degree of activity, and response to global warming are not yet well understood. In this context, this work aims to show the potential of the Sentinel-1-based interferometric technique (DInSAR) to map active rock glaciers at a regional level. In particular, the paper presents an active rock glacier inventory for the study area, which covers approximately 40,000 km2, ranging from latitude 30°21′S to 33°21′S. A total of 2116 active rock glaciers have been detected, and their elevations show a high correlation with the west-east direction. This result was obtained by using only 16 interferometric pairs. Compared to other remote sensing classification techniques, the interferometric technique offers a means to measure surface displacement (active rock glacier). This results in a reliable classification of the degree of activity compared to other methods, based on geomorphological, geomorphometric, and/or ecological criteria. This work presents evidence of this aspect by comparing the obtained results with existing optical data-based inventories. We conclude that the combination of both types of sensors (radar and optical) is an appropriate procedure for active rock glacier inventories, as both mapping methodologies are complementary.

Monitoring Rock Glacier Kinematics with Satellite Synthetic Aperture Radar

“…In this context, satellite InSAR has a high potential for studying rock glacier kinematics over Remote Sens. 2020, 12, 559 6 of 24 large areas of the semiarid Chilean/Argentinean Andes in order to improve our understanding of regional dynamics of rock glaciers, as well as to investigate local cases [33,65].…”

“…In addition, recently, repeated UAV surveys have been performed for Dos Lenguas (Argentina, Figure 1e, [64]) and El Paso rock glaciers. In this context, satellite InSAR has a high potential for studying rock glacier kinematics over large areas of the semiarid Chilean/Argentinean Andes in order to improve our understanding of regional dynamics of rock glaciers, as well as to investigate local cases [33,65].…”

“…Satellite radar interferometry (InSAR) has been efficiently used in the past to estimate rock glacier motion rates [24][25][26]. Previous work [27][28][29][30][31][32][33] has mainly involved the creation of regional inventories of rock glaciers and other periglacial processes in combination with optical data, providing outlines and state of activity (or class of motion) of the mapped landforms. The irregular acquisitions and long acquisition time intervals of past SAR missions, however, prevented the long-term monitoring of rock glacier kinematics.…”

Reconstrucción geomorfológica del último máximo glaciar en la cuenca del río San Juan, Argentina

“…16). Además los depósitos y el material morrénico servirían como fuente de detrito en la formación de glaciares rocosos, los cuales poseen una gran densidad en el área de estudio (Villarroel et al, 2018).…”

“…de nieve perenne, glaciares cubiertos y morrenas con núcleo de hielo. Y además existe un amplio desarrollo de permafrost de montaña (Forte et al, 2016;Esper Angillieri, 2017y Tapia Baldis et al, 2018, representado principalmente por la presencia de glaciares de escombros activos (Villarroel et al, 2018).…”