Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica
The cryoconite holes of the McMurdo Dry Valleys are simple, closed biogeochemical systems involving water, ice, mineral and organic debris, which serve as ecosystems for consortia of microorganisms. This study is the first to document the seasonal and annual chemical evolution of solutes in cryoconi...
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ftportlandstate:oai:pdxscholar.library.pdx.edu:geog_fac-1014 2023-05-15T13:58:46+02:00 Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica Bagshaw, Elizabeth A. Tranter, Martyn Fountain, Andrew G. Welch, Kathleen A. Basagic, Hassan J. Lyons, W. Berry 2007-12-21T08:00:00Z application/pdf https://pdxscholar.library.pdx.edu/geog_fac/15 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1014&context=geog_fac unknown PDXScholar https://pdxscholar.library.pdx.edu/geog_fac/15 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1014&context=geog_fac Geography Faculty Publications and Presentations McMurdo Dry Valleys (Antarctica) Glaciers -- Antarctica -- Taylor Valley Microbial ecology -- Antarctica Biogeochemistry -- Cold regions Environmental Sciences Geology Glaciology text 2007 ftportlandstate 2022-01-09T19:25:32Z The cryoconite holes of the McMurdo Dry Valleys are simple, closed biogeochemical systems involving water, ice, mineral and organic debris, which serve as ecosystems for consortia of microorganisms. This study is the first to document the seasonal and annual chemical evolution of solutes in cryoconite holes. Samples of glacier ice, frozen cryoconite holes and those containing water were collected during the austral summer of 2005–2006. The isolation age was calculated from the excess Cl‾ in the holes, and varied from 0 to 5 years (a), consistent with the last hot summer when the cryoconite holes were open to the atmosphere. The holes progressively deepen with isolation age. Variations in DIC, DOC, K⁺ and SO²⁻₄ suggest that dissolution of primary minerals in the cryoconite debris, cyclical precipitation and dissolution of secondary carbonates, net photosynthesis over summer and net respiration during the autumnal freeze are the principal reactions which perturb the seasonal and annual solute concentrations in the holes. DOC is generated in the holes at a rate of 7.5 μg C cm⁻² a⁻¹, and non-sea-salt K⁺ accumulates in frozen holes at a rate of 0.073 μeq cm⁻² a⁻¹. We infer that C cycling is complex even in these otherwise simple systems. Text Antarc* Antarctica Canada Glacier glacier* McMurdo Dry Valleys Portland State University: PDXScholar Austral Canada Canada Glacier ENVELOPE(162.983,162.983,-77.617,-77.617) Glacier Taylor ENVELOPE(162.167,162.167,-77.733,-77.733) McMurdo Dry Valleys Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) |
institution |
Open Polar |
collection |
Portland State University: PDXScholar |
op_collection_id |
ftportlandstate |
language |
unknown |
topic |
McMurdo Dry Valleys (Antarctica) Glaciers -- Antarctica -- Taylor Valley Microbial ecology -- Antarctica Biogeochemistry -- Cold regions Environmental Sciences Geology Glaciology |
spellingShingle |
McMurdo Dry Valleys (Antarctica) Glaciers -- Antarctica -- Taylor Valley Microbial ecology -- Antarctica Biogeochemistry -- Cold regions Environmental Sciences Geology Glaciology Bagshaw, Elizabeth A. Tranter, Martyn Fountain, Andrew G. Welch, Kathleen A. Basagic, Hassan J. Lyons, W. Berry Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica |
topic_facet |
McMurdo Dry Valleys (Antarctica) Glaciers -- Antarctica -- Taylor Valley Microbial ecology -- Antarctica Biogeochemistry -- Cold regions Environmental Sciences Geology Glaciology |
description |
The cryoconite holes of the McMurdo Dry Valleys are simple, closed biogeochemical systems involving water, ice, mineral and organic debris, which serve as ecosystems for consortia of microorganisms. This study is the first to document the seasonal and annual chemical evolution of solutes in cryoconite holes. Samples of glacier ice, frozen cryoconite holes and those containing water were collected during the austral summer of 2005–2006. The isolation age was calculated from the excess Cl‾ in the holes, and varied from 0 to 5 years (a), consistent with the last hot summer when the cryoconite holes were open to the atmosphere. The holes progressively deepen with isolation age. Variations in DIC, DOC, K⁺ and SO²⁻₄ suggest that dissolution of primary minerals in the cryoconite debris, cyclical precipitation and dissolution of secondary carbonates, net photosynthesis over summer and net respiration during the autumnal freeze are the principal reactions which perturb the seasonal and annual solute concentrations in the holes. DOC is generated in the holes at a rate of 7.5 μg C cm⁻² a⁻¹, and non-sea-salt K⁺ accumulates in frozen holes at a rate of 0.073 μeq cm⁻² a⁻¹. We infer that C cycling is complex even in these otherwise simple systems. |
format |
Text |
author |
Bagshaw, Elizabeth A. Tranter, Martyn Fountain, Andrew G. Welch, Kathleen A. Basagic, Hassan J. Lyons, W. Berry |
author_facet |
Bagshaw, Elizabeth A. Tranter, Martyn Fountain, Andrew G. Welch, Kathleen A. Basagic, Hassan J. Lyons, W. Berry |
author_sort |
Bagshaw, Elizabeth A. |
title |
Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica |
title_short |
Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica |
title_full |
Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica |
title_fullStr |
Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica |
title_full_unstemmed |
Biogeochemical Evolution of Cryoconite Holes on Canada Glacier, Taylor Valley, Antarctica |
title_sort |
biogeochemical evolution of cryoconite holes on canada glacier, taylor valley, antarctica |
publisher |
PDXScholar |
publishDate |
2007 |
url |
https://pdxscholar.library.pdx.edu/geog_fac/15 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1014&context=geog_fac |
long_lat |
ENVELOPE(162.983,162.983,-77.617,-77.617) ENVELOPE(162.167,162.167,-77.733,-77.733) ENVELOPE(163.000,163.000,-77.617,-77.617) |
geographic |
Austral Canada Canada Glacier Glacier Taylor McMurdo Dry Valleys Taylor Valley |
geographic_facet |
Austral Canada Canada Glacier Glacier Taylor McMurdo Dry Valleys Taylor Valley |
genre |
Antarc* Antarctica Canada Glacier glacier* McMurdo Dry Valleys |
genre_facet |
Antarc* Antarctica Canada Glacier glacier* McMurdo Dry Valleys |
op_source |
Geography Faculty Publications and Presentations |
op_relation |
https://pdxscholar.library.pdx.edu/geog_fac/15 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1014&context=geog_fac |
_version_ |
1766267105138704384 |