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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Bibliographic Details
Published in:The Cryosphere
Main Authors: O. Glowacki, G. B. Deane
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2020
Subjects:
geo
Online Access: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
id fttriple:oai:gotriple.eu:oai:doaj.org/article:50cf33d66cd74e9598fbee8802f142d3
record_format openpolar
spelling 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
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic geo
envir
spellingShingle 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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