Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling
We constrain the Holocene development of the active Bleis Marscha rock glacier (Err–Julier area, eastern Swiss Alps) with 15 cosmogenic nuclide exposure ages (10Be, 36Cl), horizontal surface creep rate quantification by correlating two orthophotos from 2003 and 2012, and finite element modeling. We...
Published in: | The Cryosphere |
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Copernicus Publications
2021
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Online Access: | https://doi.org/10.5194/tc-15-2057-2021 https://tc.copernicus.org/articles/15/2057/2021/tc-15-2057-2021.pdf https://doaj.org/article/47d936874e1344e0a28f409567055d05 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:47d936874e1344e0a28f409567055d05 2023-05-15T16:37:49+02:00 Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling D. Amschwand S. Ivy-Ochs M. Frehner O. Steinemann M. Christl C. Vockenhuber 2021-04-01 https://doi.org/10.5194/tc-15-2057-2021 https://tc.copernicus.org/articles/15/2057/2021/tc-15-2057-2021.pdf https://doaj.org/article/47d936874e1344e0a28f409567055d05 en eng Copernicus Publications doi:10.5194/tc-15-2057-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/2057/2021/tc-15-2057-2021.pdf https://doaj.org/article/47d936874e1344e0a28f409567055d05 undefined The Cryosphere, Vol 15, Pp 2057-2081 (2021) geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2021 fttriple https://doi.org/10.5194/tc-15-2057-2021 2023-01-22T19:11:55Z We constrain the Holocene development of the active Bleis Marscha rock glacier (Err–Julier area, eastern Swiss Alps) with 15 cosmogenic nuclide exposure ages (10Be, 36Cl), horizontal surface creep rate quantification by correlating two orthophotos from 2003 and 2012, and finite element modeling. We used the latter to separate the control on surface movement exerted by topography and material properties. Bleis Marscha is a stack of three overriding lobes whose formation phases are separated by time gaps expressed morphologically as over-steepened terrain steps and kinematically as a sharp downslope decrease in surface movement. The three discrete formation phases appear to be correlated to major Holocene climate shifts: Early Holocene low-elevation lobes (∼8.9–8.0 ka, after the Younger Dryas), Middle Holocene lobe (∼5.2–4.8 ka, after the Middle Holocene warm period), and Late Holocene high-elevation lobes (active since ∼2.8 ka, intermittently coexisting with oscillating Bleis Marscha cirque glacierets). The formation phases appear to be controlled in the source area by the climate-sensitive accumulation of an ice-debris mixture in proportions susceptible to rock glacier creep. The ongoing cohesive movement of the older generations requires ice at a depth which is possibly as old as its Early–Middle Holocene debris mantle. Permafrost degradation is attenuated by “thermal filtering” of the coarse debris boulder mantle and implies that the dynamics of the Bleis Marscha lobes that once formed persisted over millennia are less sensitive to climate. The cosmogenic radionuclide inventories of boulders on a moving rock glacier ideally record time since deposition on the rock glacier root but are stochastically altered by boulder instabilities and erosional processes. This work contributes to deciphering the long-term development and the past to quasi-present climate sensitivity of rock glaciers. Article in Journal/Newspaper Ice permafrost The Cryosphere Unknown The Cryosphere 15 4 2057 2081 |
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English |
topic |
geo |
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geo D. Amschwand S. Ivy-Ochs M. Frehner O. Steinemann M. Christl C. Vockenhuber Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
topic_facet |
geo |
description |
We constrain the Holocene development of the active Bleis Marscha rock glacier (Err–Julier area, eastern Swiss Alps) with 15 cosmogenic nuclide exposure ages (10Be, 36Cl), horizontal surface creep rate quantification by correlating two orthophotos from 2003 and 2012, and finite element modeling. We used the latter to separate the control on surface movement exerted by topography and material properties. Bleis Marscha is a stack of three overriding lobes whose formation phases are separated by time gaps expressed morphologically as over-steepened terrain steps and kinematically as a sharp downslope decrease in surface movement. The three discrete formation phases appear to be correlated to major Holocene climate shifts: Early Holocene low-elevation lobes (∼8.9–8.0 ka, after the Younger Dryas), Middle Holocene lobe (∼5.2–4.8 ka, after the Middle Holocene warm period), and Late Holocene high-elevation lobes (active since ∼2.8 ka, intermittently coexisting with oscillating Bleis Marscha cirque glacierets). The formation phases appear to be controlled in the source area by the climate-sensitive accumulation of an ice-debris mixture in proportions susceptible to rock glacier creep. The ongoing cohesive movement of the older generations requires ice at a depth which is possibly as old as its Early–Middle Holocene debris mantle. Permafrost degradation is attenuated by “thermal filtering” of the coarse debris boulder mantle and implies that the dynamics of the Bleis Marscha lobes that once formed persisted over millennia are less sensitive to climate. The cosmogenic radionuclide inventories of boulders on a moving rock glacier ideally record time since deposition on the rock glacier root but are stochastically altered by boulder instabilities and erosional processes. This work contributes to deciphering the long-term development and the past to quasi-present climate sensitivity of rock glaciers. |
format |
Article in Journal/Newspaper |
author |
D. Amschwand S. Ivy-Ochs M. Frehner O. Steinemann M. Christl C. Vockenhuber |
author_facet |
D. Amschwand S. Ivy-Ochs M. Frehner O. Steinemann M. Christl C. Vockenhuber |
author_sort |
D. Amschwand |
title |
Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
title_short |
Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
title_full |
Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
title_fullStr |
Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
title_full_unstemmed |
Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
title_sort |
deciphering the evolution of the bleis marscha rock glacier (val d'err, eastern switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-2057-2021 https://tc.copernicus.org/articles/15/2057/2021/tc-15-2057-2021.pdf https://doaj.org/article/47d936874e1344e0a28f409567055d05 |
genre |
Ice permafrost The Cryosphere |
genre_facet |
Ice permafrost The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 2057-2081 (2021) |
op_relation |
doi:10.5194/tc-15-2057-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/2057/2021/tc-15-2057-2021.pdf https://doaj.org/article/47d936874e1344e0a28f409567055d05 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-15-2057-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
4 |
container_start_page |
2057 |
op_container_end_page |
2081 |
_version_ |
1766028122156695552 |