Quantifying iceberg calving fluxes with underwater noise
Accurate estimates of calving fluxes are essential in understanding small-scale glacier dynamics and quantifying the contribution of marine-terminating glaciers to both eustatic sea-level rise (SLR) and the freshwater budget of polar regions. Here we investigate the application of acoustical oceanog...
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Copernicus Publications
2020
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fttriple:oai:gotriple.eu:oai:doaj.org/article:50cf33d66cd74e9598fbee8802f142d3 2023-05-15T16:22:16+02:00 Quantifying iceberg calving fluxes with underwater noise O. Glowacki G. B. Deane 2020-03-01 https://doi.org/10.5194/tc-14-1025-2020 https://www.the-cryosphere.net/14/1025/2020/tc-14-1025-2020.pdf https://doaj.org/article/50cf33d66cd74e9598fbee8802f142d3 en eng Copernicus Publications doi:10.5194/tc-14-1025-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/1025/2020/tc-14-1025-2020.pdf https://doaj.org/article/50cf33d66cd74e9598fbee8802f142d3 undefined The Cryosphere, Vol 14, Pp 1025-1042 (2020) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/tc-14-1025-2020 2023-01-22T18:10:27Z Accurate estimates of calving fluxes are essential in understanding small-scale glacier dynamics and quantifying the contribution of marine-terminating glaciers to both eustatic sea-level rise (SLR) and the freshwater budget of polar regions. Here we investigate the application of acoustical oceanography to measure calving flux using the underwater sounds of iceberg–water impact. A combination of time-lapse photography and passive acoustics is used to determine the relationship between the mass and impact noise of 169 icebergs generated by subaerial calving events from Hansbreen, Svalbard. The analysis includes three major factors affecting the observed noise: (1) time dependency of the thermohaline structure, (2) variability in the ocean depth along the waveguide and (3) reflection of impact noise from the glacier terminus. A correlation of 0.76 is found between the (log-transformed) kinetic energy of the falling iceberg and the corresponding measured acoustic energy corrected for these three factors. An error-in-variables linear regression is applied to estimate the coefficients of this relationship. Energy conversion coefficients for non-transformed variables are 8×10-7 and 0.92, respectively, for the multiplication factor and exponent of the power law. This simple model can be used to measure solid ice discharge from Hansbreen. Uncertainty in the estimate is a function of the number of calving events observed; 50 % uncertainty is expected for eight blocks dropping to 20 % and 10 %, respectively, for 40 and 135 calving events. It may be possible to lower these errors if the influence of different calving styles on the received noise spectra can be determined. Article in Journal/Newspaper glacier Svalbard The Cryosphere Unknown Hansbreen ENVELOPE(15.650,15.650,77.075,77.075) Svalbard The Cryosphere 14 3 1025 1042 |
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Open Polar |
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language |
English |
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geo envir |
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geo envir O. Glowacki G. B. Deane Quantifying iceberg calving fluxes with underwater noise |
topic_facet |
geo envir |
description |
Accurate estimates of calving fluxes are essential in understanding small-scale glacier dynamics and quantifying the contribution of marine-terminating glaciers to both eustatic sea-level rise (SLR) and the freshwater budget of polar regions. Here we investigate the application of acoustical oceanography to measure calving flux using the underwater sounds of iceberg–water impact. A combination of time-lapse photography and passive acoustics is used to determine the relationship between the mass and impact noise of 169 icebergs generated by subaerial calving events from Hansbreen, Svalbard. The analysis includes three major factors affecting the observed noise: (1) time dependency of the thermohaline structure, (2) variability in the ocean depth along the waveguide and (3) reflection of impact noise from the glacier terminus. A correlation of 0.76 is found between the (log-transformed) kinetic energy of the falling iceberg and the corresponding measured acoustic energy corrected for these three factors. An error-in-variables linear regression is applied to estimate the coefficients of this relationship. Energy conversion coefficients for non-transformed variables are 8×10-7 and 0.92, respectively, for the multiplication factor and exponent of the power law. This simple model can be used to measure solid ice discharge from Hansbreen. Uncertainty in the estimate is a function of the number of calving events observed; 50 % uncertainty is expected for eight blocks dropping to 20 % and 10 %, respectively, for 40 and 135 calving events. It may be possible to lower these errors if the influence of different calving styles on the received noise spectra can be determined. |
format |
Article in Journal/Newspaper |
author |
O. Glowacki G. B. Deane |
author_facet |
O. Glowacki G. B. Deane |
author_sort |
O. Glowacki |
title |
Quantifying iceberg calving fluxes with underwater noise |
title_short |
Quantifying iceberg calving fluxes with underwater noise |
title_full |
Quantifying iceberg calving fluxes with underwater noise |
title_fullStr |
Quantifying iceberg calving fluxes with underwater noise |
title_full_unstemmed |
Quantifying iceberg calving fluxes with underwater noise |
title_sort |
quantifying iceberg calving fluxes with underwater noise |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-1025-2020 https://www.the-cryosphere.net/14/1025/2020/tc-14-1025-2020.pdf https://doaj.org/article/50cf33d66cd74e9598fbee8802f142d3 |
long_lat |
ENVELOPE(15.650,15.650,77.075,77.075) |
geographic |
Hansbreen Svalbard |
geographic_facet |
Hansbreen Svalbard |
genre |
glacier Svalbard The Cryosphere |
genre_facet |
glacier Svalbard The Cryosphere |
op_source |
The Cryosphere, Vol 14, Pp 1025-1042 (2020) |
op_relation |
doi:10.5194/tc-14-1025-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/1025/2020/tc-14-1025-2020.pdf https://doaj.org/article/50cf33d66cd74e9598fbee8802f142d3 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-14-1025-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
3 |
container_start_page |
1025 |
op_container_end_page |
1042 |
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1766010236314845184 |