Densification of layered firn in the ice sheet at Dome Fuji, Antarctica
ABSTRACT In order to better understand the densification of polar firn, firn cores from the three sites within ~10 km of Dome Fuji, Antarctica, were investigated using surrogates of density: dielectric permittivities ε v and ε h at microwave frequencies with electrical fields in the vertical and hor...
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crcambridgeupr:10.1017/jog.2016.16 2024-03-03T08:38:11+00:00 Densification of layered firn in the ice sheet at Dome Fuji, Antarctica FUJITA, SHUJI GOTO-AZUMA, KUMIKO HIRABAYASHI, MOTOHIRO HORI, AKIRA IIZUKA, YOSHINORI MOTIZUKI, YUKO MOTOYAMA, HIDEAKI TAKAHASHI, KAZUYA 2016 http://dx.doi.org/10.1017/jog.2016.16 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000162 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 62, issue 231, page 103-123 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.16 2024-02-08T08:33:49Z ABSTRACT In order to better understand the densification of polar firn, firn cores from the three sites within ~10 km of Dome Fuji, Antarctica, were investigated using surrogates of density: dielectric permittivities ε v and ε h at microwave frequencies with electrical fields in the vertical and horizontal planes respectively. Dielectric anisotropy Δ ε (= ε v − ε h ) was then examined as a surrogate of the anisotropic geometry of firn. We find that layered densification is explained as a result of complex effects of two phenomena that commonly occur at the three sites. Basically, layers with initially smaller density and smaller geometrical anisotropy deform preferentially throughout the densification process due to textural effects. Second, layers having a higher concentration of Cl − ions deform preferentially during a limited period from the near surface depths until smoothing out of layered Cl − ions by diffusion. We hypothesize that Cl − ions dissociated from sea salts soften firn due to modulation of dislocation movement. Moreover, firn differs markedly across the three sites in terms of strength of geometrical anisotropy, mean rate of densification and density fluctuation. We hypothesize that these differences are caused by textural effects resulting from differences in depositional conditions within various spatial scales. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Journal of Glaciology Cambridge University Press Dome Fuji ENVELOPE(39.700,39.700,-77.317,-77.317) Journal of Glaciology 62 231 103 123 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes FUJITA, SHUJI GOTO-AZUMA, KUMIKO HIRABAYASHI, MOTOHIRO HORI, AKIRA IIZUKA, YOSHINORI MOTIZUKI, YUKO MOTOYAMA, HIDEAKI TAKAHASHI, KAZUYA Densification of layered firn in the ice sheet at Dome Fuji, Antarctica |
topic_facet |
Earth-Surface Processes |
description |
ABSTRACT In order to better understand the densification of polar firn, firn cores from the three sites within ~10 km of Dome Fuji, Antarctica, were investigated using surrogates of density: dielectric permittivities ε v and ε h at microwave frequencies with electrical fields in the vertical and horizontal planes respectively. Dielectric anisotropy Δ ε (= ε v − ε h ) was then examined as a surrogate of the anisotropic geometry of firn. We find that layered densification is explained as a result of complex effects of two phenomena that commonly occur at the three sites. Basically, layers with initially smaller density and smaller geometrical anisotropy deform preferentially throughout the densification process due to textural effects. Second, layers having a higher concentration of Cl − ions deform preferentially during a limited period from the near surface depths until smoothing out of layered Cl − ions by diffusion. We hypothesize that Cl − ions dissociated from sea salts soften firn due to modulation of dislocation movement. Moreover, firn differs markedly across the three sites in terms of strength of geometrical anisotropy, mean rate of densification and density fluctuation. We hypothesize that these differences are caused by textural effects resulting from differences in depositional conditions within various spatial scales. |
format |
Article in Journal/Newspaper |
author |
FUJITA, SHUJI GOTO-AZUMA, KUMIKO HIRABAYASHI, MOTOHIRO HORI, AKIRA IIZUKA, YOSHINORI MOTIZUKI, YUKO MOTOYAMA, HIDEAKI TAKAHASHI, KAZUYA |
author_facet |
FUJITA, SHUJI GOTO-AZUMA, KUMIKO HIRABAYASHI, MOTOHIRO HORI, AKIRA IIZUKA, YOSHINORI MOTIZUKI, YUKO MOTOYAMA, HIDEAKI TAKAHASHI, KAZUYA |
author_sort |
FUJITA, SHUJI |
title |
Densification of layered firn in the ice sheet at Dome Fuji, Antarctica |
title_short |
Densification of layered firn in the ice sheet at Dome Fuji, Antarctica |
title_full |
Densification of layered firn in the ice sheet at Dome Fuji, Antarctica |
title_fullStr |
Densification of layered firn in the ice sheet at Dome Fuji, Antarctica |
title_full_unstemmed |
Densification of layered firn in the ice sheet at Dome Fuji, Antarctica |
title_sort |
densification of layered firn in the ice sheet at dome fuji, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/jog.2016.16 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000162 |
long_lat |
ENVELOPE(39.700,39.700,-77.317,-77.317) |
geographic |
Dome Fuji |
geographic_facet |
Dome Fuji |
genre |
Antarc* Antarctica Ice Sheet Journal of Glaciology |
genre_facet |
Antarc* Antarctica Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 62, issue 231, page 103-123 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2016.16 |
container_title |
Journal of Glaciology |
container_volume |
62 |
container_issue |
231 |
container_start_page |
103 |
op_container_end_page |
123 |
_version_ |
1792505332542472192 |