Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature
Measurements of ^(84)Kr/^(36)Ar ratios in Greenland ice show that gravitational separation in the firn layer is responsible for the enrichments relative to atmospheric ratios. The ^(84)Kr/^(36)Ar ratio is enriched by 12.8 per mil and is 24 times the ^(18)O/^(16)O enrichment in trapped O_2, as predic...
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American Association for the Advancement of Science
1996
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ftcaltechauth:oai:authors.library.caltech.edu:52842 2023-05-15T16:28:55+02:00 Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature Craig, H. Wiens, R. C. 1996-03-22 https://authors.library.caltech.edu/52842/ https://resolver.caltech.edu/CaltechAUTHORS:20141216-082509059 unknown American Association for the Advancement of Science Craig, H. and Wiens, R. C. (1996) Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature. Science, 271 (5256). pp. 1708-1710. ISSN 0036-8075. doi:10.1126/science.271.5256.1708. https://resolver.caltech.edu/CaltechAUTHORS:20141216-082509059 <https://resolver.caltech.edu/CaltechAUTHORS:20141216-082509059> Article PeerReviewed 1996 ftcaltechauth https://doi.org/10.1126/science.271.5256.1708 2021-11-11T19:01:42Z Measurements of ^(84)Kr/^(36)Ar ratios in Greenland ice show that gravitational separation in the firn layer is responsible for the enrichments relative to atmospheric ratios. The ^(84)Kr/^(36)Ar ratio is enriched by 12.8 per mil and is 24 times the ^(18)O/^(16)O enrichment in trapped O_2, as predicted for gravitational fractionation. Because gravitational enrichment depends on firn thickness, which in turn depends on annual mean temperature, noble gas ratios provide a method for determining paleotemperatures and ancient firn thicknesses in polar ice caps. The gravitational effects are modulated by about 10 to 15 percent by atmospheric concentration changes caused by temperature effects on oceanic gas solubilities. The availability of five noble gases should make it possible to deconvolute the solubility and gravitational enrichments for calibration of ^(18)O paleotemperatures throughout the polar ice sheets. Article in Journal/Newspaper Greenland Caltech Authors (California Institute of Technology) Greenland Science 271 5256 1708 1710 |
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Caltech Authors (California Institute of Technology) |
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description |
Measurements of ^(84)Kr/^(36)Ar ratios in Greenland ice show that gravitational separation in the firn layer is responsible for the enrichments relative to atmospheric ratios. The ^(84)Kr/^(36)Ar ratio is enriched by 12.8 per mil and is 24 times the ^(18)O/^(16)O enrichment in trapped O_2, as predicted for gravitational fractionation. Because gravitational enrichment depends on firn thickness, which in turn depends on annual mean temperature, noble gas ratios provide a method for determining paleotemperatures and ancient firn thicknesses in polar ice caps. The gravitational effects are modulated by about 10 to 15 percent by atmospheric concentration changes caused by temperature effects on oceanic gas solubilities. The availability of five noble gases should make it possible to deconvolute the solubility and gravitational enrichments for calibration of ^(18)O paleotemperatures throughout the polar ice sheets. |
format |
Article in Journal/Newspaper |
author |
Craig, H. Wiens, R. C. |
spellingShingle |
Craig, H. Wiens, R. C. Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature |
author_facet |
Craig, H. Wiens, R. C. |
author_sort |
Craig, H. |
title |
Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature |
title_short |
Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature |
title_full |
Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature |
title_fullStr |
Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature |
title_full_unstemmed |
Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature |
title_sort |
gravitational enrichment of ^(84)kr/^(36)ar ratios in polar ice caps: a measure of firn thickness and accumulation temperature |
publisher |
American Association for the Advancement of Science |
publishDate |
1996 |
url |
https://authors.library.caltech.edu/52842/ https://resolver.caltech.edu/CaltechAUTHORS:20141216-082509059 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
Craig, H. and Wiens, R. C. (1996) Gravitational Enrichment of ^(84)Kr/^(36)Ar Ratios in Polar Ice Caps: A Measure of Firn Thickness and Accumulation Temperature. Science, 271 (5256). pp. 1708-1710. ISSN 0036-8075. doi:10.1126/science.271.5256.1708. https://resolver.caltech.edu/CaltechAUTHORS:20141216-082509059 <https://resolver.caltech.edu/CaltechAUTHORS:20141216-082509059> |
op_doi |
https://doi.org/10.1126/science.271.5256.1708 |
container_title |
Science |
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271 |
container_issue |
5256 |
container_start_page |
1708 |
op_container_end_page |
1710 |
_version_ |
1766018601371828224 |