Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts

• Published in: Permafrost and Periglacial Processes
• Main Authors: Sébastien Monnier, Christophe Kinnard
• Format: Article in Journal/Newspaper
• Language: unknown
• Subjects: Long Rock
• Online Access: https://doi.org/10.1002/ppp.1846

Using ground‐penetrating radar (GPR), we studied an entire 2.2 km long rock glacier (3780–4350 m asl) in the dry Andes of Chile with the aim of inferring its composition. In the high‐quality, unmigrated data, we identified the active layer base and the rock glacier floor. In between, hyperbolae generated by diffracting boulders were inventoried; the ones along the rock glacier floor (n = 51) allowed determination of the average electromagnetic (EM) velocity in the rock glacier, the latter being further used for migration. Within the rock glacier (16–39 m thick), the EM velocity varies between 0.076 and 0.167 m.ns‐1; the main stratigraphic features observed are upward‐dipping reflectors. The low EM velocities (