The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice
It is vital to understand the mechanical properties of flowing ice to model the dynamics of ice sheets and ice shelves and to predict their behaviour in the future. We can increase our understanding of ice physical properties by performing deformation experiments on ice in laboratories and examining...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2021
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-15-2235-2021 https://doaj.org/article/6045c4a9c9524f8f903727c553847f4c |
id |
ftdoajarticles:oai:doaj.org/article:6045c4a9c9524f8f903727c553847f4c |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:6045c4a9c9524f8f903727c553847f4c 2023-05-15T16:41:58+02:00 The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice L. Craw A. Treverrow S. Fan M. Peternell S. Cook F. McCormack J. Roberts 2021-05-01T00:00:00Z https://doi.org/10.5194/tc-15-2235-2021 https://doaj.org/article/6045c4a9c9524f8f903727c553847f4c EN eng Copernicus Publications https://tc.copernicus.org/articles/15/2235/2021/tc-15-2235-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-2235-2021 1994-0416 1994-0424 https://doaj.org/article/6045c4a9c9524f8f903727c553847f4c The Cryosphere, Vol 15, Pp 2235-2250 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-2235-2021 2022-12-31T07:35:16Z It is vital to understand the mechanical properties of flowing ice to model the dynamics of ice sheets and ice shelves and to predict their behaviour in the future. We can increase our understanding of ice physical properties by performing deformation experiments on ice in laboratories and examining its mechanical and microstructural responses. However, natural conditions in ice sheets and ice shelves extend to low temperatures ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>≪</mo><mo>-</mo><mn mathvariant="normal">10</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="36pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="1be5049de7f8a69fcd20dac38a5ac4c9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-2235-2021-ie00001.svg" width="36pt" height="10pt" src="tc-15-2235-2021-ie00001.png"/></svg:svg> ∘ C), and high octahedral strains ( > 0.08), and emulating these conditions in laboratory experiments can take an impractically long time. It is possible to accelerate an experiment by running it at a higher temperature in the early stages and then lowering the temperature to meet the target conditions once the tertiary creep stage is reached. This can reduce total experiment run-time by > 1000 h; however it is not known whether this could affect the final strain rate or microstructure of the ice and potentially introduce a bias into the data. We deformed polycrystalline ice samples in uniaxial compression at −2 ∘ C before lowering the temperature to either −7 or −10 ∘ C, and we compared the results to constant-temperature experiments. Tertiary strain rates adjusted to the change in temperature very quickly (within 3 % of the total experiment run-time), with no significant deviation from strain rates measured in constant-temperature experiments. In experiments with a smaller temperature step ( −2 to −7 ∘ C) ... Article in Journal/Newspaper Ice Shelves The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 15 5 2235 2250 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 L. Craw A. Treverrow S. Fan M. Peternell S. Cook F. McCormack J. Roberts The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
It is vital to understand the mechanical properties of flowing ice to model the dynamics of ice sheets and ice shelves and to predict their behaviour in the future. We can increase our understanding of ice physical properties by performing deformation experiments on ice in laboratories and examining its mechanical and microstructural responses. However, natural conditions in ice sheets and ice shelves extend to low temperatures ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>≪</mo><mo>-</mo><mn mathvariant="normal">10</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="36pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="1be5049de7f8a69fcd20dac38a5ac4c9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-2235-2021-ie00001.svg" width="36pt" height="10pt" src="tc-15-2235-2021-ie00001.png"/></svg:svg> ∘ C), and high octahedral strains ( > 0.08), and emulating these conditions in laboratory experiments can take an impractically long time. It is possible to accelerate an experiment by running it at a higher temperature in the early stages and then lowering the temperature to meet the target conditions once the tertiary creep stage is reached. This can reduce total experiment run-time by > 1000 h; however it is not known whether this could affect the final strain rate or microstructure of the ice and potentially introduce a bias into the data. We deformed polycrystalline ice samples in uniaxial compression at −2 ∘ C before lowering the temperature to either −7 or −10 ∘ C, and we compared the results to constant-temperature experiments. Tertiary strain rates adjusted to the change in temperature very quickly (within 3 % of the total experiment run-time), with no significant deviation from strain rates measured in constant-temperature experiments. In experiments with a smaller temperature step ( −2 to −7 ∘ C) ... |
format |
Article in Journal/Newspaper |
author |
L. Craw A. Treverrow S. Fan M. Peternell S. Cook F. McCormack J. Roberts |
author_facet |
L. Craw A. Treverrow S. Fan M. Peternell S. Cook F. McCormack J. Roberts |
author_sort |
L. Craw |
title |
The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
title_short |
The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
title_full |
The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
title_fullStr |
The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
title_full_unstemmed |
The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
title_sort |
temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-2235-2021 https://doaj.org/article/6045c4a9c9524f8f903727c553847f4c |
genre |
Ice Shelves The Cryosphere |
genre_facet |
Ice Shelves The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 2235-2250 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/2235/2021/tc-15-2235-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-2235-2021 1994-0416 1994-0424 https://doaj.org/article/6045c4a9c9524f8f903727c553847f4c |
op_doi |
https://doi.org/10.5194/tc-15-2235-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
5 |
container_start_page |
2235 |
op_container_end_page |
2250 |
_version_ |
1766032441038864384 |