Causes and Processes of Thermo‐Erosional Gully Initiation Near Tiksi Settlement, Arctic Eastern Siberia
ABSTRACT Climatic and environmental change is leading to increased frequency and intensity of permafrost degradation processes; however, our knowledge of their mechanisms and rate is still limited. We examined structure of deposits, surface topography, and weather conditions during the initiation of...
| Published in: | Permafrost and Periglacial Processes |
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| Main Authors: | , , , , |
| Other Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
2024
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1002/ppp.2229 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2229 |
| Summary: | ABSTRACT Climatic and environmental change is leading to increased frequency and intensity of permafrost degradation processes; however, our knowledge of their mechanisms and rate is still limited. We examined structure of deposits, surface topography, and weather conditions during the initiation of a thermo‐erosion gully in eastern Siberia and monitored its changes between 2020 and 2022. The initiation of the gully was caused by a combination of processes: (1) the catchment area of the gully was artificially increased several decades ago as a result of the interception of runoff by the winter road; (2) ice‐wedge degradation led to surface runoff concentration above the gully head, while a large volume of ground ice remained in other parts of the slope, and frost cracking continued; (3) the entry of water into frost cracks formed underground tunnels; and (4) high air temperatures and heavy rainfall immediately before the gully appearance resulted in the expansion of the tunnels and collapse of their roof. In 2 years, the volume of the gully reached 1000 m 3 at least 40% of that volume consists of ground ice. The gully development did not significantly change the water chemistry due to significant water freshening caused by melting of ground ice. |
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