Identifying mountain permafrost degradation by repeating historical electrical resistivity tomography (ERT) measurements
<p>Ongoing global warming intensifies the degradation of permafrost. Permafrost thawing impacts landform evolution, reduces freshwater resources, enhances the potential of natural hazards and thus has significant socio-economic impacts. Electrical resistivity tomography (ERT) has been widely u...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-07-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2919/2023/tc-17-2919-2023.pdf |
| Summary: | <p>Ongoing global warming intensifies the degradation of permafrost. Permafrost
thawing impacts landform evolution, reduces freshwater resources, enhances
the potential of natural hazards and thus has significant socio-economic
impacts. Electrical resistivity tomography (ERT) has been widely used to map
the ice-containing permafrost by its resistivity contrast compared to the
surrounding unfrozen medium. This study aims to reveal the effects of
ongoing climate warming on mountain permafrost by repeating historical ERT
and analyzing the temporal changes in the resistivity distribution. In order
to facilitate the measurements, we introduce and discuss the employment of
textile electrodes. These newly developed electrodes significantly reduce
working effort, are easy to deploy on blocky surfaces and yield
sufficiently low contact resistances. We analyze permafrost evolution on
three periglacial landforms (two rock glaciers and one talus slope) in the
Swiss and Austrian Alps by repeating historical surveys after 10, 12 and 16 years, respectively. The resistivity values have been significantly reduced
in ice-poor permafrost landforms at all study sites. Interestingly,
resistivity values related to ice-rich permafrost in the studied active rock
glacier partly increased during the studied time period. To explain this
apparently counterintuitive (in view of increased resistivity) observation,
geomorphological circumstances, such as the relief and increased creep
velocity of the active rock glacier, are discussed by using additional
remote sensing data. The present study highlights ice-poor permafrost
degradation in the Alps resulting from ever-accelerating global warming.</p> |
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| ISSN: | 1994-0416 1994-0424 |