On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica
Motivated by the possibility of comparing theoretical predictions of Lake Vostok's composition with future in situ measurements, we investigated the composition of clathrates that are expected to form in this environment from the air supplied to the lake by melting ice. To establish the best po...
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Online Access: | https://digitalcommons.usf.edu/geo_facpub/615 https://doi.org/10.1089/ast.2012.0907 https://arxiv.org/pdf/1301.2009v1.pdf |
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ftusouthflorida:oai:digitalcommons.usf.edu:geo_facpub-1614 2023-07-30T03:56:52+02:00 On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica Mousis, Olivier Lakhlifi, Azzedine Picaud, Sylvain Pasek, Matthew A. Chassefière, Eric 2013-04-01T07:00:00Z https://digitalcommons.usf.edu/geo_facpub/615 https://doi.org/10.1089/ast.2012.0907 https://arxiv.org/pdf/1301.2009v1.pdf unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/geo_facpub/615 doi:10.1089/ast.2012.0907 https://arxiv.org/pdf/1301.2009v1.pdf default School of Geosciences Faculty and Staff Publications Earth Sciences article 2013 ftusouthflorida https://doi.org/10.1089/ast.2012.0907 2023-07-13T20:27:31Z Motivated by the possibility of comparing theoretical predictions of Lake Vostok's composition with future in situ measurements, we investigated the composition of clathrates that are expected to form in this environment from the air supplied to the lake by melting ice. To establish the best possible correlation between the lake water composition and that of air clathrates formed in situ, we used a statistical thermodynamic model based on the description of the guest-clathrate interaction by a spherically averaged Kihara potential with a nominal set of potential parameters. We determined the fugacities of the different volatiles present in the lake by defining a “pseudo” pure substance dissolved in water owning the average properties of the mixture and by using the Redlich-Kwong equation of state to mimic its thermodynamic behavior. Irrespective of the clathrate structure considered in our model, we found that xenon and krypton are strongly impoverished in the lake water (a ratio in the 0.04–0.1 range for xenon and a ratio in the ∼0.15–0.3 range for krypton) compared to their atmospheric abundances. Argon and methane were also found to be depleted in the Lake Vostok water by factors in the 0.5–0.95 and 0.3–0.5 ranges, respectively, compared to their atmospheric abundances. On the other hand, the carbon dioxide abundance was found to be substantially enriched in the lake water compared to its atmospheric abundance (by a factor in the 1.6–5 range at 200 residence times). The comparison of our predictions of the CO2 and CH4 mole fractions in Lake Vostok with future in situ measurements will allow disentangling between the possible supply sources. Key Words: Lake Vostok—Subglacial lakes—Composition—Clathrates—Statistical thermodynamic model. Article in Journal/Newspaper Antarc* Antarctica University of South Florida St. Petersburg: Digital USFSP Lake Vostok ENVELOPE(106.000,106.000,-77.500,-77.500) Astrobiology 13 4 380 390 |
institution |
Open Polar |
collection |
University of South Florida St. Petersburg: Digital USFSP |
op_collection_id |
ftusouthflorida |
language |
unknown |
topic |
Earth Sciences |
spellingShingle |
Earth Sciences Mousis, Olivier Lakhlifi, Azzedine Picaud, Sylvain Pasek, Matthew A. Chassefière, Eric On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica |
topic_facet |
Earth Sciences |
description |
Motivated by the possibility of comparing theoretical predictions of Lake Vostok's composition with future in situ measurements, we investigated the composition of clathrates that are expected to form in this environment from the air supplied to the lake by melting ice. To establish the best possible correlation between the lake water composition and that of air clathrates formed in situ, we used a statistical thermodynamic model based on the description of the guest-clathrate interaction by a spherically averaged Kihara potential with a nominal set of potential parameters. We determined the fugacities of the different volatiles present in the lake by defining a “pseudo” pure substance dissolved in water owning the average properties of the mixture and by using the Redlich-Kwong equation of state to mimic its thermodynamic behavior. Irrespective of the clathrate structure considered in our model, we found that xenon and krypton are strongly impoverished in the lake water (a ratio in the 0.04–0.1 range for xenon and a ratio in the ∼0.15–0.3 range for krypton) compared to their atmospheric abundances. Argon and methane were also found to be depleted in the Lake Vostok water by factors in the 0.5–0.95 and 0.3–0.5 ranges, respectively, compared to their atmospheric abundances. On the other hand, the carbon dioxide abundance was found to be substantially enriched in the lake water compared to its atmospheric abundance (by a factor in the 1.6–5 range at 200 residence times). The comparison of our predictions of the CO2 and CH4 mole fractions in Lake Vostok with future in situ measurements will allow disentangling between the possible supply sources. Key Words: Lake Vostok—Subglacial lakes—Composition—Clathrates—Statistical thermodynamic model. |
format |
Article in Journal/Newspaper |
author |
Mousis, Olivier Lakhlifi, Azzedine Picaud, Sylvain Pasek, Matthew A. Chassefière, Eric |
author_facet |
Mousis, Olivier Lakhlifi, Azzedine Picaud, Sylvain Pasek, Matthew A. Chassefière, Eric |
author_sort |
Mousis, Olivier |
title |
On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica |
title_short |
On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica |
title_full |
On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica |
title_fullStr |
On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica |
title_full_unstemmed |
On the Abundances of Noble and Biologically Relevant Gases in Lake Vostok, Antarctica |
title_sort |
on the abundances of noble and biologically relevant gases in lake vostok, antarctica |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2013 |
url |
https://digitalcommons.usf.edu/geo_facpub/615 https://doi.org/10.1089/ast.2012.0907 https://arxiv.org/pdf/1301.2009v1.pdf |
long_lat |
ENVELOPE(106.000,106.000,-77.500,-77.500) |
geographic |
Lake Vostok |
geographic_facet |
Lake Vostok |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
School of Geosciences Faculty and Staff Publications |
op_relation |
https://digitalcommons.usf.edu/geo_facpub/615 doi:10.1089/ast.2012.0907 https://arxiv.org/pdf/1301.2009v1.pdf |
op_rights |
default |
op_doi |
https://doi.org/10.1089/ast.2012.0907 |
container_title |
Astrobiology |
container_volume |
13 |
container_issue |
4 |
container_start_page |
380 |
op_container_end_page |
390 |
_version_ |
1772814967294132224 |