Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving
Oceanic changes before and after the relocation of iceberg B9B and calving of the Mertz Glacier Tongue (MGT) in February 2010 are examined on the continental shelf off the Adelie Land/George V Land coast, East Antarctica. Summer hydrographic observations, including stable oxygen isotope ratio (delta...
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Online Access: | http://hdl.handle.net/2115/68326 https://doi.org/10.1002/2017JC012925 |
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fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/68326 2023-05-15T13:04:20+02:00 Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving Aoki, S. Kobayashi, R. Rintoul, S. R. Tamura, T. Kusahara, K. http://hdl.handle.net/2115/68326 https://doi.org/10.1002/2017JC012925 eng eng American Geophysical Union http://hdl.handle.net/2115/68326 Journal of Geophysical Research Oceans, 122(8): 6277-6294 http://dx.doi.org/10.1002/2017JC012925 Copyright 2017 American Geophysical Union. Antarctica glacier tongue iceberg circulation change stable oxygen isotope ratio freshening article fthokunivhus https://doi.org/10.1002/2017JC012925 2022-11-18T01:04:30Z Oceanic changes before and after the relocation of iceberg B9B and calving of the Mertz Glacier Tongue (MGT) in February 2010 are examined on the continental shelf off the Adelie Land/George V Land coast, East Antarctica. Summer hydrographic observations, including stable oxygen isotope ratio (delta O-18), in 2001/2008 and 2011/2015 and results of a numerical model are used. Along the western flank of the MGT, temperature decreased between 2001 and 2015 for most of the water column in the Adelie Depression. delta O-18 generally decreased, especially at the MGT draft depths on the northern side. West of the MGT, temperature, salinity, and delta O-18 decreased in the intermediate layer. East of the MGT, in contrast, temperature increased between 2001 and 2011 at intermediate depths, salinity increased in the intermediate and deep layers, and delta O-18 slightly decreased in the deep layer but did not change much around 300 dbar. The numerical experiment exhibits a change in ocean circulation, revealing an increase in modified Circumpolar Deep Water (mCDW) inflow in the east and a decrease in the west. The contrasting changes in mCDW intrusion are consistent between the observations and numerical model, and are indicative of the effect of removal of the ice barriers. The contrast is overlain by overall decreases in salinity and delta O-18, which suggests an increase in the continental meltwater fraction of 5-20% and might reveal a wide-ranging influence from West Antarctica. The oxygen isotope ratio is, hence, effective in monitoring the increase in continental melt over the Antarctic shelf. Article in Journal/Newspaper Adelie Land Antarc* Antarctic Antarctica East Antarctica George V Land Iceberg* Mertz Glacier West Antarctica Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Adelie Depression ENVELOPE(146.000,146.000,-67.417,-67.417) Antarctic East Antarctica George V Land ENVELOPE(148.000,148.000,-68.500,-68.500) Mertz Glacier ENVELOPE(144.500,144.500,-67.667,-67.667) Mertz Glacier Tongue ENVELOPE(145.500,145.500,-67.167,-67.167) The Antarctic West Antarctica Journal of Geophysical Research: Oceans 122 8 6277 6294 |
institution |
Open Polar |
collection |
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
op_collection_id |
fthokunivhus |
language |
English |
topic |
Antarctica glacier tongue iceberg circulation change stable oxygen isotope ratio freshening |
spellingShingle |
Antarctica glacier tongue iceberg circulation change stable oxygen isotope ratio freshening Aoki, S. Kobayashi, R. Rintoul, S. R. Tamura, T. Kusahara, K. Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving |
topic_facet |
Antarctica glacier tongue iceberg circulation change stable oxygen isotope ratio freshening |
description |
Oceanic changes before and after the relocation of iceberg B9B and calving of the Mertz Glacier Tongue (MGT) in February 2010 are examined on the continental shelf off the Adelie Land/George V Land coast, East Antarctica. Summer hydrographic observations, including stable oxygen isotope ratio (delta O-18), in 2001/2008 and 2011/2015 and results of a numerical model are used. Along the western flank of the MGT, temperature decreased between 2001 and 2015 for most of the water column in the Adelie Depression. delta O-18 generally decreased, especially at the MGT draft depths on the northern side. West of the MGT, temperature, salinity, and delta O-18 decreased in the intermediate layer. East of the MGT, in contrast, temperature increased between 2001 and 2011 at intermediate depths, salinity increased in the intermediate and deep layers, and delta O-18 slightly decreased in the deep layer but did not change much around 300 dbar. The numerical experiment exhibits a change in ocean circulation, revealing an increase in modified Circumpolar Deep Water (mCDW) inflow in the east and a decrease in the west. The contrasting changes in mCDW intrusion are consistent between the observations and numerical model, and are indicative of the effect of removal of the ice barriers. The contrast is overlain by overall decreases in salinity and delta O-18, which suggests an increase in the continental meltwater fraction of 5-20% and might reveal a wide-ranging influence from West Antarctica. The oxygen isotope ratio is, hence, effective in monitoring the increase in continental melt over the Antarctic shelf. |
format |
Article in Journal/Newspaper |
author |
Aoki, S. Kobayashi, R. Rintoul, S. R. Tamura, T. Kusahara, K. |
author_facet |
Aoki, S. Kobayashi, R. Rintoul, S. R. Tamura, T. Kusahara, K. |
author_sort |
Aoki, S. |
title |
Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving |
title_short |
Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving |
title_full |
Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving |
title_fullStr |
Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving |
title_full_unstemmed |
Changes in water properties and flow regime on the continental shelf off the Adelie/George V Land coast, East Antarctica, after glacier tongue calving |
title_sort |
changes in water properties and flow regime on the continental shelf off the adelie/george v land coast, east antarctica, after glacier tongue calving |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/2115/68326 https://doi.org/10.1002/2017JC012925 |
long_lat |
ENVELOPE(146.000,146.000,-67.417,-67.417) ENVELOPE(148.000,148.000,-68.500,-68.500) ENVELOPE(144.500,144.500,-67.667,-67.667) ENVELOPE(145.500,145.500,-67.167,-67.167) |
geographic |
Adelie Depression Antarctic East Antarctica George V Land Mertz Glacier Mertz Glacier Tongue The Antarctic West Antarctica |
geographic_facet |
Adelie Depression Antarctic East Antarctica George V Land Mertz Glacier Mertz Glacier Tongue The Antarctic West Antarctica |
genre |
Adelie Land Antarc* Antarctic Antarctica East Antarctica George V Land Iceberg* Mertz Glacier West Antarctica |
genre_facet |
Adelie Land Antarc* Antarctic Antarctica East Antarctica George V Land Iceberg* Mertz Glacier West Antarctica |
op_relation |
http://hdl.handle.net/2115/68326 Journal of Geophysical Research Oceans, 122(8): 6277-6294 http://dx.doi.org/10.1002/2017JC012925 |
op_rights |
Copyright 2017 American Geophysical Union. |
op_doi |
https://doi.org/10.1002/2017JC012925 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
122 |
container_issue |
8 |
container_start_page |
6277 |
op_container_end_page |
6294 |
_version_ |
1766357360512598016 |