The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)

A rapid sequence of cascading events involving thermokarst lake outburst, local rock glacier front failure, debris flow development, and river blockage hit Radurschl Valley (Ötztal Alps, Tyrol) on 13 August 2019. Compounding effects from permafrost degradation and drainage network development within...

Full description

Bibliographic Details
Published in:Natural Hazards and Earth System Sciences
Main Authors: Seelig, Simon, Wagner, Thomas, Krainer, Karl, Avian, Michael, Olefs, Marc, Haslinger, Klaus, Winkler, Gerfried
Format: Text
Language:English
Published: 2023
Subjects:
Online Access:https://doi.org/10.5194/nhess-23-2547-2023
https://nhess.copernicus.org/articles/23/2547/2023/
id ftcopernicus:oai:publications.copernicus.org:nhess104883
record_format openpolar
spelling ftcopernicus:oai:publications.copernicus.org:nhess104883 2023-08-15T12:42:47+02:00 The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps) Seelig, Simon Wagner, Thomas Krainer, Karl Avian, Michael Olefs, Marc Haslinger, Klaus Winkler, Gerfried 2023-07-20 application/pdf https://doi.org/10.5194/nhess-23-2547-2023 https://nhess.copernicus.org/articles/23/2547/2023/ eng eng doi:10.5194/nhess-23-2547-2023 https://nhess.copernicus.org/articles/23/2547/2023/ eISSN: 1684-9981 Text 2023 ftcopernicus https://doi.org/10.5194/nhess-23-2547-2023 2023-07-24T16:24:16Z A rapid sequence of cascading events involving thermokarst lake outburst, local rock glacier front failure, debris flow development, and river blockage hit Radurschl Valley (Ötztal Alps, Tyrol) on 13 August 2019. Compounding effects from permafrost degradation and drainage network development within the rock glacier initiated the complex process chain. The debris flow dammed the main river of the valley, impounding a water volume of 120 000 m 3 that was partly drained by excavation to prevent a potentially catastrophic outburst flood. We present a systematic analysis of destabilizing factors to deduce the failure mechanism. The identification and evaluation of individual factors reveals a critical combination of topographical and sedimentological disposition, climate, and weather patterns driving the evolution of a thermokarst drainage network. Progressively changing groundwater flow and storage patterns within the frozen sediment accumulation governed the slope stability of the rock glacier front. Our results demonstrate the hazard potential of active rock glaciers due to their large amount of mobilizable sediment, dynamically changing internal structure, thermokarst lake development, and substantial water flow along a rapidly evolving channel network. Text permafrost Thermokarst Copernicus Publications: E-Journals Natural Hazards and Earth System Sciences 23 7 2547 2568
institution Open Polar
collection Copernicus Publications: E-Journals
op_collection_id ftcopernicus
language English
description A rapid sequence of cascading events involving thermokarst lake outburst, local rock glacier front failure, debris flow development, and river blockage hit Radurschl Valley (Ötztal Alps, Tyrol) on 13 August 2019. Compounding effects from permafrost degradation and drainage network development within the rock glacier initiated the complex process chain. The debris flow dammed the main river of the valley, impounding a water volume of 120 000 m 3 that was partly drained by excavation to prevent a potentially catastrophic outburst flood. We present a systematic analysis of destabilizing factors to deduce the failure mechanism. The identification and evaluation of individual factors reveals a critical combination of topographical and sedimentological disposition, climate, and weather patterns driving the evolution of a thermokarst drainage network. Progressively changing groundwater flow and storage patterns within the frozen sediment accumulation governed the slope stability of the rock glacier front. Our results demonstrate the hazard potential of active rock glaciers due to their large amount of mobilizable sediment, dynamically changing internal structure, thermokarst lake development, and substantial water flow along a rapidly evolving channel network.
format Text
author Seelig, Simon
Wagner, Thomas
Krainer, Karl
Avian, Michael
Olefs, Marc
Haslinger, Klaus
Winkler, Gerfried
spellingShingle Seelig, Simon
Wagner, Thomas
Krainer, Karl
Avian, Michael
Olefs, Marc
Haslinger, Klaus
Winkler, Gerfried
The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)
author_facet Seelig, Simon
Wagner, Thomas
Krainer, Karl
Avian, Michael
Olefs, Marc
Haslinger, Klaus
Winkler, Gerfried
author_sort Seelig, Simon
title The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)
title_short The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)
title_full The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)
title_fullStr The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)
title_full_unstemmed The role of thermokarst evolution in debris flow initiation (Hüttekar Rock Glacier, Austrian Alps)
title_sort role of thermokarst evolution in debris flow initiation (hüttekar rock glacier, austrian alps)
publishDate 2023
url https://doi.org/10.5194/nhess-23-2547-2023
https://nhess.copernicus.org/articles/23/2547/2023/
genre permafrost
Thermokarst
genre_facet permafrost
Thermokarst
op_source eISSN: 1684-9981
op_relation doi:10.5194/nhess-23-2547-2023
https://nhess.copernicus.org/articles/23/2547/2023/
op_doi https://doi.org/10.5194/nhess-23-2547-2023
container_title Natural Hazards and Earth System Sciences
container_volume 23
container_issue 7
container_start_page 2547
op_container_end_page 2568
_version_ 1774297420137496576