Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing.
During the 1986/87 and 1987/88 Italian Antarctic expeditions a number of ice samples were col~ected f~om different locations. Sixty-five samples coming mainly from the Hells Gate and Backstairs Passage ice shelves have been studied for their -oxygen isotopic composition. Very negative <5 180 valu...
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ftunivpisairis:oai:arpi.unipi.it:11568/17117 2024-01-28T10:01:01+01:00 Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. BARONI, CARLO STENNI B IACUMIN P. Baroni, Carlo Stenni, B Iacumin, P. 1991 STAMPA http://hdl.handle.net/11568/17117 http://www.socgeol.info/Ricerca/pubblicazioni.asp?act=see&type=Memorie&y=1991&v=46&f= eng eng volume:46 firstpage:46 lastpage:48 numberofpages:3 journal:MEMORIE DELLA SOCIETA' GEOLOGICA ITALIANA http://hdl.handle.net/11568/17117 http://www.socgeol.info/Ricerca/pubblicazioni.asp?act=see&type=Memorie&y=1991&v=46&f= ice shelf Stable Isotope Terra Nova Bay Antarctica Ross Sea info:eu-repo/semantics/article 1991 ftunivpisairis 2024-01-03T17:42:35Z During the 1986/87 and 1987/88 Italian Antarctic expeditions a number of ice samples were col~ected f~om different locations. Sixty-five samples coming mainly from the Hells Gate and Backstairs Passage ice shelves have been studied for their -oxygen isotopic composition. Very negative <5 180 values are characteristic of continental snowfall in Antarctica /(aroun.fl:-21±3 per mil for snow deposited near the coastal area). The <5180 values obtained from seawater edge ice and ice beneath dirt cones range from -0.80 to +2.66 per mil, suggesting that the origin of this ice is essentially from seawater freezing. This is also proven by the finding of shells and skeletons of I?arine organisms included in the ice and is in agreement with the conclusions of previous studies on Antarctic ice shelves. Ice samples from the upper section of dirt cones show <5 180 values from -12.68 to -6.15 per mil, which are intermediate between those of seawater ice and continental ice. These values are probably explained by the mixing of water from the melting of the snowdrift ice capping the cones and the seawater ice forming their main body. The ice core of the moraine of Corner Glacier, further inland, shows <5 180 values from -31.81 to -26.40, in agreement with a continental origin of the ice. This ice is clearly formed by snow which fell at higher elevations, as proven by the remarkable 180 depletion of these samples as compared to local snowfall. It is apparent that the origin of ice can be well identified by isotope measurements, irrespective of sample location and appearance. Article in Journal/Newspaper Antarc* Antarctic Antarctica ice core Ice Shelf Ice Shelves Ross Sea Victoria Land ARPI - Archivio della Ricerca dell'Università di Pisa Antarctic Corner Glacier ENVELOPE(163.667,163.667,-74.450,-74.450) Hells Gate ENVELOPE(163.800,163.800,-74.850,-74.850) Ross Sea Terra Nova Bay The Cones ENVELOPE(78.344,78.344,-68.635,-68.635) Victoria Land |
institution |
Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
topic |
ice shelf Stable Isotope Terra Nova Bay Antarctica Ross Sea |
spellingShingle |
ice shelf Stable Isotope Terra Nova Bay Antarctica Ross Sea BARONI, CARLO STENNI B IACUMIN P. Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. |
topic_facet |
ice shelf Stable Isotope Terra Nova Bay Antarctica Ross Sea |
description |
During the 1986/87 and 1987/88 Italian Antarctic expeditions a number of ice samples were col~ected f~om different locations. Sixty-five samples coming mainly from the Hells Gate and Backstairs Passage ice shelves have been studied for their -oxygen isotopic composition. Very negative <5 180 values are characteristic of continental snowfall in Antarctica /(aroun.fl:-21±3 per mil for snow deposited near the coastal area). The <5180 values obtained from seawater edge ice and ice beneath dirt cones range from -0.80 to +2.66 per mil, suggesting that the origin of this ice is essentially from seawater freezing. This is also proven by the finding of shells and skeletons of I?arine organisms included in the ice and is in agreement with the conclusions of previous studies on Antarctic ice shelves. Ice samples from the upper section of dirt cones show <5 180 values from -12.68 to -6.15 per mil, which are intermediate between those of seawater ice and continental ice. These values are probably explained by the mixing of water from the melting of the snowdrift ice capping the cones and the seawater ice forming their main body. The ice core of the moraine of Corner Glacier, further inland, shows <5 180 values from -31.81 to -26.40, in agreement with a continental origin of the ice. This ice is clearly formed by snow which fell at higher elevations, as proven by the remarkable 180 depletion of these samples as compared to local snowfall. It is apparent that the origin of ice can be well identified by isotope measurements, irrespective of sample location and appearance. |
author2 |
Baroni, Carlo Stenni, B Iacumin, P. |
format |
Article in Journal/Newspaper |
author |
BARONI, CARLO STENNI B IACUMIN P. |
author_facet |
BARONI, CARLO STENNI B IACUMIN P. |
author_sort |
BARONI, CARLO |
title |
Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. |
title_short |
Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. |
title_full |
Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. |
title_fullStr |
Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. |
title_full_unstemmed |
Oxygen isotopic composition of ice samples from the Hells Gate and Backstairs Passage ice shelves (Northern Victoria Land, Antarctica): evidence for bottom freezing. |
title_sort |
oxygen isotopic composition of ice samples from the hells gate and backstairs passage ice shelves (northern victoria land, antarctica): evidence for bottom freezing. |
publishDate |
1991 |
url |
http://hdl.handle.net/11568/17117 http://www.socgeol.info/Ricerca/pubblicazioni.asp?act=see&type=Memorie&y=1991&v=46&f= |
long_lat |
ENVELOPE(163.667,163.667,-74.450,-74.450) ENVELOPE(163.800,163.800,-74.850,-74.850) ENVELOPE(78.344,78.344,-68.635,-68.635) |
geographic |
Antarctic Corner Glacier Hells Gate Ross Sea Terra Nova Bay The Cones Victoria Land |
geographic_facet |
Antarctic Corner Glacier Hells Gate Ross Sea Terra Nova Bay The Cones Victoria Land |
genre |
Antarc* Antarctic Antarctica ice core Ice Shelf Ice Shelves Ross Sea Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica ice core Ice Shelf Ice Shelves Ross Sea Victoria Land |
op_relation |
volume:46 firstpage:46 lastpage:48 numberofpages:3 journal:MEMORIE DELLA SOCIETA' GEOLOGICA ITALIANA http://hdl.handle.net/11568/17117 http://www.socgeol.info/Ricerca/pubblicazioni.asp?act=see&type=Memorie&y=1991&v=46&f= |
_version_ |
1789325698372993024 |