Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica
The Japanese Antarctic Research Expedition (JARE) has continued glaciological work in Mizuho Plateau, East Antarctica. We have already reported that the ice sheet on Mizuho Plateau which flows into Shirase Glacier, classified as a fast-moving outlet glacier, was thinning at a rate of about 70cm・a^&l...
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ftnipr:oai:nipr.repo.nii.ac.jp:00003569 2023-05-15T13:49:00+02:00 Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica Fumihiko Nishio Shinji Mae Hirokazu Ohmae Shuhei Takahashi Masayoshi Nakawo Kunio Kawada 1989-08 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3569 http://id.nii.ac.jp/1291/00003569/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3569&item_no=1&attribute_id=18&file_no=1 en eng National Institute of Polar Research/Department of Applied Physics,Faculty of Engineering, Hokkaido University/Institute of Low Temperature Science, Hokkaido University/Kitami Institute of Technology/Nagaoka Institute of Snow and Ice Studies, National Research Center for Disaster Prevention, Science and Technology Agency/Faculty of Science, Toyama University National Institute of Polar Research https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3569 http://id.nii.ac.jp/1291/00003569/ AA10756213 Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology, 2, 97-104(1989-08) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3569&item_no=1&attribute_id=18&file_no=1 Departmental Bulletin Paper P(論文) 1989 ftnipr 2022-12-10T19:45:40Z The Japanese Antarctic Research Expedition (JARE) has continued glaciological work in Mizuho Plateau, East Antarctica. We have already reported that the ice sheet on Mizuho Plateau which flows into Shirase Glacier, classified as a fast-moving outlet glacier, was thinning at a rate of about 70cm・a^<-1> and the profile of basal shear stress along the central flow line derived from topographic map was similar to that of surging glaciers. A new 5-year glaciological program in Mizuho Plateau and East Queen Maud Land which started in 1981 is now being carried out. We have obtained new results as follows : (1) The ice sheet in the downstream region where ice elevation is lower than about 2800m is thinning, based upon data on horizontal and vertical flow velocity, strain rate, inclination of ice surface, accumulation rate and densification of snow. (2) The result of the radio-echo sounding on Mizuho Plateau suggests that the base of the ice sheet in the downstream region is wet. Based upon a two-dimensional numerical model, the calculated bottom temperature shows that the ice temperature at the base of the ice sheet in the glacier downstream is at the pressure melting point and the ice base is also wet. These results supports the result described in (1), since basal sliding due to the wet base causes the ice sheet thinning as proposed by our previous studies. Summarizing these results, a possible explanation of ice sheet variation on Mizuho Plateau is as follows : the thinning of the ice sheet caused by the basal sliding due to melting of the ice base started at the mouth of the Shirase Glacier and has been expanding upstream to reach the present state. A simple calculation, using flow velocities, shows that the thinning started at Shirase Glacier about a few thousand years ago. Report Antarc* Antarctic Antarctica East Antarctica Ice Sheet Polar meteorology and glaciology Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology Queen Maud Land Shirase Glacier National Institute of Polar Research Repository, Japan Antarctic East Antarctica Mizuho ENVELOPE(44.317,44.317,-70.683,-70.683) Queen Maud Land ENVELOPE(12.000,12.000,-72.500,-72.500) Mizuho Plateau ENVELOPE(40.000,40.000,-73.000,-73.000) Shirase Glacier ENVELOPE(39.000,39.000,-70.333,-70.333) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
description |
The Japanese Antarctic Research Expedition (JARE) has continued glaciological work in Mizuho Plateau, East Antarctica. We have already reported that the ice sheet on Mizuho Plateau which flows into Shirase Glacier, classified as a fast-moving outlet glacier, was thinning at a rate of about 70cm・a^<-1> and the profile of basal shear stress along the central flow line derived from topographic map was similar to that of surging glaciers. A new 5-year glaciological program in Mizuho Plateau and East Queen Maud Land which started in 1981 is now being carried out. We have obtained new results as follows : (1) The ice sheet in the downstream region where ice elevation is lower than about 2800m is thinning, based upon data on horizontal and vertical flow velocity, strain rate, inclination of ice surface, accumulation rate and densification of snow. (2) The result of the radio-echo sounding on Mizuho Plateau suggests that the base of the ice sheet in the downstream region is wet. Based upon a two-dimensional numerical model, the calculated bottom temperature shows that the ice temperature at the base of the ice sheet in the glacier downstream is at the pressure melting point and the ice base is also wet. These results supports the result described in (1), since basal sliding due to the wet base causes the ice sheet thinning as proposed by our previous studies. Summarizing these results, a possible explanation of ice sheet variation on Mizuho Plateau is as follows : the thinning of the ice sheet caused by the basal sliding due to melting of the ice base started at the mouth of the Shirase Glacier and has been expanding upstream to reach the present state. A simple calculation, using flow velocities, shows that the thinning started at Shirase Glacier about a few thousand years ago. |
format |
Report |
author |
Fumihiko Nishio Shinji Mae Hirokazu Ohmae Shuhei Takahashi Masayoshi Nakawo Kunio Kawada |
spellingShingle |
Fumihiko Nishio Shinji Mae Hirokazu Ohmae Shuhei Takahashi Masayoshi Nakawo Kunio Kawada Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica |
author_facet |
Fumihiko Nishio Shinji Mae Hirokazu Ohmae Shuhei Takahashi Masayoshi Nakawo Kunio Kawada |
author_sort |
Fumihiko Nishio |
title |
Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica |
title_short |
Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica |
title_full |
Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica |
title_fullStr |
Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica |
title_full_unstemmed |
Dynamical behavior of the ice sheet in Mizuho Plateau, East Antarctica |
title_sort |
dynamical behavior of the ice sheet in mizuho plateau, east antarctica |
publisher |
National Institute of Polar Research/Department of Applied Physics,Faculty of Engineering, Hokkaido University/Institute of Low Temperature Science, Hokkaido University/Kitami Institute of Technology/Nagaoka Institute of Snow and Ice Studies, National Research Center for Disaster Prevention, Science and Technology Agency/Faculty of Science, Toyama University |
publishDate |
1989 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3569 http://id.nii.ac.jp/1291/00003569/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3569&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(44.317,44.317,-70.683,-70.683) ENVELOPE(12.000,12.000,-72.500,-72.500) ENVELOPE(40.000,40.000,-73.000,-73.000) ENVELOPE(39.000,39.000,-70.333,-70.333) |
geographic |
Antarctic East Antarctica Mizuho Queen Maud Land Mizuho Plateau Shirase Glacier |
geographic_facet |
Antarctic East Antarctica Mizuho Queen Maud Land Mizuho Plateau Shirase Glacier |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Polar meteorology and glaciology Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology Queen Maud Land Shirase Glacier |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Polar meteorology and glaciology Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology Queen Maud Land Shirase Glacier |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3569 http://id.nii.ac.jp/1291/00003569/ AA10756213 Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology, 2, 97-104(1989-08) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3569&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766250410265280512 |