Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska
Much of the world's ice enters the ocean via outlet glaciers terminating in fjords. Inside fjords, icebergs may affect glacier–ocean interactions by cooling incoming ocean waters, enhancing vertical mixing, or providing back stress on the terminus. However, relatively few studies have been perf...
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Language: | English |
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Copernicus Publications
2019
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Online Access: | https://doi.org/10.5194/tc-13-1785-2019 https://doaj.org/article/3108520b7c364560a61d55e194ddbdab |
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ftdoajarticles:oai:doaj.org/article:3108520b7c364560a61d55e194ddbdab 2023-05-15T16:20:38+02:00 Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska S. U. Neuhaus S. M. Tulaczyk C. Branecky Begeman 2019-07-01T00:00:00Z https://doi.org/10.5194/tc-13-1785-2019 https://doaj.org/article/3108520b7c364560a61d55e194ddbdab EN eng Copernicus Publications https://www.the-cryosphere.net/13/1785/2019/tc-13-1785-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-1785-2019 1994-0416 1994-0424 https://doaj.org/article/3108520b7c364560a61d55e194ddbdab The Cryosphere, Vol 13, Pp 1785-1799 (2019) Environmental sciences GE1-350 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/tc-13-1785-2019 2022-12-30T21:32:15Z Much of the world's ice enters the ocean via outlet glaciers terminating in fjords. Inside fjords, icebergs may affect glacier–ocean interactions by cooling incoming ocean waters, enhancing vertical mixing, or providing back stress on the terminus. However, relatively few studies have been performed on iceberg dynamics inside fjords, particularly outside of Greenland. We examine icebergs calved from Columbia Glacier, Alaska, over 8 months spanning late winter to mid-fall using 0.5 m resolution satellite imagery, identifying icebergs based on pixel brightness. Iceberg sizes fit a power-law distribution with an overall power-law exponent, m , of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">1.26</mn><mo>±</mo><mn mathvariant="normal">0.05</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="f35c24ab1184fe0ceb4a3ef4dcd5d0ae"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-1785-2019-ie00001.svg" width="64pt" height="10pt" src="tc-13-1785-2019-ie00001.png"/></svg:svg> . Seasonal variations in the power-law exponent indicate that brittle fracture of icebergs is more prevalent in the summer months. Combining our results with those from previous studies of iceberg distributions, we find that iceberg calving rate, rather than water temperature, appears to be the major control on the exponent value. We also analyze icebergs' spatial distribution inside the fjord and find that large icebergs (10 000–100 000 m 2 cross-sectional area) have low spatial correlation with icebergs of smaller sizes due to their tendency to ground on shallow regions. We estimate the surface area of icebergs in contact with incoming seawater to be <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" ... Article in Journal/Newspaper glacier glacier glaciers Greenland The Cryosphere Alaska Directory of Open Access Journals: DOAJ Articles Greenland The Cryosphere 13 7 1785 1799 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 S. U. Neuhaus S. M. Tulaczyk C. Branecky Begeman Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Much of the world's ice enters the ocean via outlet glaciers terminating in fjords. Inside fjords, icebergs may affect glacier–ocean interactions by cooling incoming ocean waters, enhancing vertical mixing, or providing back stress on the terminus. However, relatively few studies have been performed on iceberg dynamics inside fjords, particularly outside of Greenland. We examine icebergs calved from Columbia Glacier, Alaska, over 8 months spanning late winter to mid-fall using 0.5 m resolution satellite imagery, identifying icebergs based on pixel brightness. Iceberg sizes fit a power-law distribution with an overall power-law exponent, m , of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">1.26</mn><mo>±</mo><mn mathvariant="normal">0.05</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="f35c24ab1184fe0ceb4a3ef4dcd5d0ae"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-1785-2019-ie00001.svg" width="64pt" height="10pt" src="tc-13-1785-2019-ie00001.png"/></svg:svg> . Seasonal variations in the power-law exponent indicate that brittle fracture of icebergs is more prevalent in the summer months. Combining our results with those from previous studies of iceberg distributions, we find that iceberg calving rate, rather than water temperature, appears to be the major control on the exponent value. We also analyze icebergs' spatial distribution inside the fjord and find that large icebergs (10 000–100 000 m 2 cross-sectional area) have low spatial correlation with icebergs of smaller sizes due to their tendency to ground on shallow regions. We estimate the surface area of icebergs in contact with incoming seawater to be <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" ... |
format |
Article in Journal/Newspaper |
author |
S. U. Neuhaus S. M. Tulaczyk C. Branecky Begeman |
author_facet |
S. U. Neuhaus S. M. Tulaczyk C. Branecky Begeman |
author_sort |
S. U. Neuhaus |
title |
Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska |
title_short |
Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska |
title_full |
Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska |
title_fullStr |
Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska |
title_full_unstemmed |
Spatiotemporal distributions of icebergs in a temperate fjord: Columbia Fjord, Alaska |
title_sort |
spatiotemporal distributions of icebergs in a temperate fjord: columbia fjord, alaska |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-1785-2019 https://doaj.org/article/3108520b7c364560a61d55e194ddbdab |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier glacier glaciers Greenland The Cryosphere Alaska |
genre_facet |
glacier glacier glaciers Greenland The Cryosphere Alaska |
op_source |
The Cryosphere, Vol 13, Pp 1785-1799 (2019) |
op_relation |
https://www.the-cryosphere.net/13/1785/2019/tc-13-1785-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-1785-2019 1994-0416 1994-0424 https://doaj.org/article/3108520b7c364560a61d55e194ddbdab |
op_doi |
https://doi.org/10.5194/tc-13-1785-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
7 |
container_start_page |
1785 |
op_container_end_page |
1799 |
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1766008561796644864 |