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...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/483164 2023-08-20T04:07:09+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 Amschwand, Dominik Ivy-Ochs, Susan Frehner, Marcel id_orcid:0 000-0001-9970-3870 Steinemann, Olivia Christl, Marcus Vockenhuber, Christof 2021 application/application/pdf https://hdl.handle.net/20.500.11850/483164 https://doi.org/10.3929/ethz-b-000483164 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-15-2057-2021 info:eu-repo/semantics/altIdentifier/wos/000644487300001 http://hdl.handle.net/20.500.11850/483164 doi:10.3929/ethz-b-000483164 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International The Cryosphere, 15 (4) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftethz https://doi.org/20.500.11850/48316410.3929/ethz-b-00048316410.5194/tc-15-2057-2021 2023-07-30T23:53:32Z 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. ISSN:1994-0416 ISSN:1994-0424 Article in Journal/Newspaper Ice permafrost The Cryosphere ETH Zürich Research Collection |
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Open Polar |
collection |
ETH Zürich Research Collection |
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ftethz |
language |
English |
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. ISSN:1994-0416 ISSN:1994-0424 |
format |
Article in Journal/Newspaper |
author |
Amschwand, Dominik Ivy-Ochs, Susan Frehner, Marcel id_orcid:0 000-0001-9970-3870 Steinemann, Olivia Christl, Marcus Vockenhuber, Christof |
spellingShingle |
Amschwand, Dominik Ivy-Ochs, Susan Frehner, Marcel id_orcid:0 000-0001-9970-3870 Steinemann, Olivia Christl, Marcus Vockenhuber, Christof 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 |
author_facet |
Amschwand, Dominik Ivy-Ochs, Susan Frehner, Marcel id_orcid:0 000-0001-9970-3870 Steinemann, Olivia Christl, Marcus Vockenhuber, Christof |
author_sort |
Amschwand, Dominik |
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 |
publishDate |
2021 |
url |
https://hdl.handle.net/20.500.11850/483164 https://doi.org/10.3929/ethz-b-000483164 |
genre |
Ice permafrost The Cryosphere |
genre_facet |
Ice permafrost The Cryosphere |
op_source |
The Cryosphere, 15 (4) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-15-2057-2021 info:eu-repo/semantics/altIdentifier/wos/000644487300001 http://hdl.handle.net/20.500.11850/483164 doi:10.3929/ethz-b-000483164 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/48316410.3929/ethz-b-00048316410.5194/tc-15-2057-2021 |
_version_ |
1774718603163074560 |