Enhanced rock‐slope failure following ice‐sheet deglaciation: timing and causes
ABSTRACT 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...
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crwiley:10.1002/esp.3495 2024-09-15T18:11:38+00:00 Enhanced rock‐slope failure following ice‐sheet deglaciation: timing and causes Ballantyne, Colin K. Wilson, Peter Gheorghiu, Delia Rodés, Àngel 2013 http://dx.doi.org/10.1002/esp.3495 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.3495 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.3495 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Earth Surface Processes and Landforms volume 39, issue 7, page 900-913 ISSN 0197-9337 1096-9837 journal-article 2013 crwiley https://doi.org/10.1002/esp.3495 2024-07-25T04:21:22Z ABSTRACT 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 ( 10 Be) 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. Copyright © 2013 John ... Article in Journal/Newspaper Ice Ice Sheet permafrost Wiley Online Library Earth Surface Processes and Landforms 39 7 900 913 |
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English |
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ABSTRACT 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 ( 10 Be) 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. Copyright © 2013 John ... |
format |
Article in Journal/Newspaper |
author |
Ballantyne, Colin K. Wilson, Peter Gheorghiu, Delia Rodés, Àngel |
spellingShingle |
Ballantyne, Colin K. Wilson, Peter Gheorghiu, Delia Rodés, Àngel Enhanced rock‐slope failure following ice‐sheet deglaciation: timing and causes |
author_facet |
Ballantyne, Colin K. Wilson, Peter Gheorghiu, Delia Rodés, Àngel |
author_sort |
Ballantyne, Colin K. |
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 |
publisher |
Wiley |
publishDate |
2013 |
url |
http://dx.doi.org/10.1002/esp.3495 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.3495 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.3495 |
genre |
Ice Ice Sheet permafrost |
genre_facet |
Ice Ice Sheet permafrost |
op_source |
Earth Surface Processes and Landforms volume 39, issue 7, page 900-913 ISSN 0197-9337 1096-9837 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
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 |
_version_ |
1810449224153694208 |