Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes
The temporal pattern of rock-slope failures (RSFs) following Late Pleistocene deglaciation on tectonically stable terrains is controversial: previous studies variously suggest (1) a rapid response due to removal of supporting ice (‘debuttressing’), (2) a progressive decline in RSF frequency, and (3)...
Published in: | Earth Surface Processes and Landforms |
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Language: | English |
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2014
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Online Access: | https://research-portal.st-andrews.ac.uk/en/researchoutput/enhanced-rockslope-failure-following-icesheet-deglaciation(17dcf600-9fb3-4bcb-be8c-456895d8106d).html https://doi.org/10.1002/esp.3495 https://research-repository.st-andrews.ac.uk/bitstream/10023/5839/1/Ballantyne_2014_ESPL_Enhanced.pdf |
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ftunstandrewcris:oai:research-portal.st-andrews.ac.uk:publications/17dcf600-9fb3-4bcb-be8c-456895d8106d 2024-06-23T07:53:39+00:00 Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes Ballantyne, Colin Wilson, Peter Gheorghiu, Delia Rodés, Àngel 2014-06-14 application/pdf https://research-portal.st-andrews.ac.uk/en/researchoutput/enhanced-rockslope-failure-following-icesheet-deglaciation(17dcf600-9fb3-4bcb-be8c-456895d8106d).html https://doi.org/10.1002/esp.3495 https://research-repository.st-andrews.ac.uk/bitstream/10023/5839/1/Ballantyne_2014_ESPL_Enhanced.pdf eng eng https://research-portal.st-andrews.ac.uk/en/researchoutput/enhanced-rockslope-failure-following-icesheet-deglaciation(17dcf600-9fb3-4bcb-be8c-456895d8106d).html info:eu-repo/semantics/openAccess Ballantyne , C , Wilson , P , Gheorghiu , D & Rodés , À 2014 , ' Enhanced rock-slope failure following ice-sheet deglaciation : timing and causes ' , Earth Surface Processes and Landforms , vol. 39 , no. 7 , pp. 900–913 . https://doi.org/10.1002/esp.3495 rock-slope failure paraglacial surface exposure dating stress release palaeoseismicity article 2014 ftunstandrewcris https://doi.org/10.1002/esp.3495 2024-06-13T00:38:10Z The temporal pattern of rock-slope failures (RSFs) following Late Pleistocene deglaciation on tectonically stable terrains is controversial: previous studies variously suggest (1) a rapid response due to removal of supporting ice (‘debuttressing’), (2) a progressive decline in RSF frequency, and (3) a millennial-scale delay before peak RSF activity. We test these competing models through beryllium-10 (10Be) exposure dating of five closely-spaced quartzite RSFs on the Isle of Jura, Scotland, to establish the relationship between timing of failure and those of deglaciation, episodes of rapid warming and periods of rapid glacio-isostatic uplift. All five dated RSFs occurred at least 720–2240 years after deglaciation, with the probability of failure peaking ~2 ka after deglaciation, consistent with millennial-scale delay model (3). This excludes debuttressing as an immediate cause of failure, though it is likely that time-dependent stress release due to deglacial unloading resulted in progressive development of failure planes within the rock. Thaw of permafrost ice in joints is unlikely to have been a prime trigger of failure as some RSFs occurred several centuries after the onset of interstadial warming. Conversely, the timespan of the RSFs coincides with the period of maximum glacio-isostatic crustal uplift, suggesting that failure was triggered by uplift-driven seismic events acting on fractured rock masses. Implications of this and related research are: (1) that retreat of the last Pleistocene ice sheets across tectonically-stable mountainous terrains was succeeded by a period of enhanced rock-slope failure due to deglacial unloading and probably uplift-driven seismicity; (2) that the great majority of RSFs in the British Isles outside the limits of Loch Lomond Stadial (= Younger Dryas) glaciation are of Lateglacial (pre-Holocene) age; and (3) numerous RSFs must also have occurred inside Loch Lomond Stadial (LLS) glacial limits, but that runout debris was removed by LLS glaciers. Article in Journal/Newspaper Ice Ice Sheet permafrost University of St Andrews: Research Portal Jura ENVELOPE(13.501,13.501,68.062,68.062) Loch Lomond ENVELOPE(-125.746,-125.746,54.239,54.239) Earth Surface Processes and Landforms 39 7 900 913 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
rock-slope failure paraglacial surface exposure dating stress release palaeoseismicity |
spellingShingle |
rock-slope failure paraglacial surface exposure dating stress release palaeoseismicity Ballantyne, Colin Wilson, Peter Gheorghiu, Delia Rodés, Àngel Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
topic_facet |
rock-slope failure paraglacial surface exposure dating stress release palaeoseismicity |
description |
The temporal pattern of rock-slope failures (RSFs) following Late Pleistocene deglaciation on tectonically stable terrains is controversial: previous studies variously suggest (1) a rapid response due to removal of supporting ice (‘debuttressing’), (2) a progressive decline in RSF frequency, and (3) a millennial-scale delay before peak RSF activity. We test these competing models through beryllium-10 (10Be) exposure dating of five closely-spaced quartzite RSFs on the Isle of Jura, Scotland, to establish the relationship between timing of failure and those of deglaciation, episodes of rapid warming and periods of rapid glacio-isostatic uplift. All five dated RSFs occurred at least 720–2240 years after deglaciation, with the probability of failure peaking ~2 ka after deglaciation, consistent with millennial-scale delay model (3). This excludes debuttressing as an immediate cause of failure, though it is likely that time-dependent stress release due to deglacial unloading resulted in progressive development of failure planes within the rock. Thaw of permafrost ice in joints is unlikely to have been a prime trigger of failure as some RSFs occurred several centuries after the onset of interstadial warming. Conversely, the timespan of the RSFs coincides with the period of maximum glacio-isostatic crustal uplift, suggesting that failure was triggered by uplift-driven seismic events acting on fractured rock masses. Implications of this and related research are: (1) that retreat of the last Pleistocene ice sheets across tectonically-stable mountainous terrains was succeeded by a period of enhanced rock-slope failure due to deglacial unloading and probably uplift-driven seismicity; (2) that the great majority of RSFs in the British Isles outside the limits of Loch Lomond Stadial (= Younger Dryas) glaciation are of Lateglacial (pre-Holocene) age; and (3) numerous RSFs must also have occurred inside Loch Lomond Stadial (LLS) glacial limits, but that runout debris was removed by LLS glaciers. |
format |
Article in Journal/Newspaper |
author |
Ballantyne, Colin Wilson, Peter Gheorghiu, Delia Rodés, Àngel |
author_facet |
Ballantyne, Colin Wilson, Peter Gheorghiu, Delia Rodés, Àngel |
author_sort |
Ballantyne, Colin |
title |
Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
title_short |
Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
title_full |
Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
title_fullStr |
Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
title_full_unstemmed |
Enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
title_sort |
enhanced rock-slope failure following ice-sheet deglaciation:timing and causes |
publishDate |
2014 |
url |
https://research-portal.st-andrews.ac.uk/en/researchoutput/enhanced-rockslope-failure-following-icesheet-deglaciation(17dcf600-9fb3-4bcb-be8c-456895d8106d).html https://doi.org/10.1002/esp.3495 https://research-repository.st-andrews.ac.uk/bitstream/10023/5839/1/Ballantyne_2014_ESPL_Enhanced.pdf |
long_lat |
ENVELOPE(13.501,13.501,68.062,68.062) ENVELOPE(-125.746,-125.746,54.239,54.239) |
geographic |
Jura Loch Lomond |
geographic_facet |
Jura Loch Lomond |
genre |
Ice Ice Sheet permafrost |
genre_facet |
Ice Ice Sheet permafrost |
op_source |
Ballantyne , C , Wilson , P , Gheorghiu , D & Rodés , À 2014 , ' Enhanced rock-slope failure following ice-sheet deglaciation : timing and causes ' , Earth Surface Processes and Landforms , vol. 39 , no. 7 , pp. 900–913 . https://doi.org/10.1002/esp.3495 |
op_relation |
https://research-portal.st-andrews.ac.uk/en/researchoutput/enhanced-rockslope-failure-following-icesheet-deglaciation(17dcf600-9fb3-4bcb-be8c-456895d8106d).html |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/esp.3495 |
container_title |
Earth Surface Processes and Landforms |
container_volume |
39 |
container_issue |
7 |
container_start_page |
900 |
op_container_end_page |
913 |
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1802645415217070080 |