EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
Andean Permafrost in Taluses and Blockslopes in the Agua Negra
Catchment, Argentina - Distribution and Hydrological Significance
Melanie A. Stammler1, Diana A. Ortiz1,2, Tamara Koehler1, and Lothar Schrott1
1Department of Geography, University of Bonn, Bonn, Germany (email@example.com)
2Department of Geophysics and Astronomy, National University of San Juan, San Juan, Argentina
Extensive areas in mountain regions are under permafrost conditions with periglacial processes in
the arid Andes of Argentina being mostly associated with high mountain permafrost. The most
visible expression of creeping mountain permafrost within the periglacial altitudinal belt (between
35º and 27ºS), is the occurrence of rock glaciers. Beside snow and ice melting, active layer thawing
and degrading permafrost contribute to river runoff; an essential resource in the arid Andes and
their forelands. Halla et al. (2021) calculated for the first time rock glacier ice content using
geophysical methods and four-phase modeling. Besides rock glaciers, taluses (including protalus
ramparts) and blockslopes are widespread above an altitude of 4000 m a.s.l., with a first
quantitative assessment revealing a surface coverage of about 73 %. We hypothesize that beside
rock glaciers, taluses and blockslopes present a high potential for ice content, having a
comparable or even more significant importance as valuable water reserves. However, taluses and
blockslopes have not yet been properly investigated and little research has focused on the
permafrost distribution and stratigraphy of these landforms.
This study determines the characteristics and the influence of climatic, topographical, and
lithological conditions on the permafrost, using a multi-method approach: Electrical Resistivity
Tomography (ERT), Seismic Refraction Tomography (SRT), hydrological monitoring along the
course of Agua Negra river (discharge, water sampling), and UAV-, as well as spaceborne remote
sensing analysis. While the use of ERT is beneficial due to the contrasting electrical resistivities of
lithological media, water and ice, SRT complements the data with detailed p-wave based
information on the upper layer. Hydrological monitoring aids in distinguishing different water
resources and in estimating their contributions to runoff. In addition, the repeated application of
remote sensing techniques allows for an acquisition of high resolution digital elevation models
with models of difference providing insight in the magnitude, timing and spatial pattern of vertical
and horizontal surface changes.
The possibility of determining with greater precision the distribution of permafrost in the arid
Andes will lead to a more accurate estimation of solid-state water reserves stored in periglacial
landforms in arid Andean catchments.
Halla, C., Blöthe, J.H., Tapia Baldis, C., Trombotto, D., Hilbich, C., Hauck, C., Schrott, L., 2021.
Ice content and interannual water storage changes of an active rock glacier in the dry