Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica
Antarctic ice sheet history is imprinted in the structure and fabric of the ice column. At ice rises, the signature of ice flow history is preserved due to the low strain rates inherent at these independent ice flow centres. We present results from a distributed acoustic sensing (DAS) experiment at...
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Copernicus Publications
2021
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Online Access: | https://doi.org/10.5194/tc-15-3443-2021 https://tc.copernicus.org/articles/15/3443/2021/tc-15-3443-2021.pdf https://doaj.org/article/a64b50a8d88247298799fb2d92f83352 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:a64b50a8d88247298799fb2d92f83352 2023-05-15T13:39:35+02:00 Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica A. M. Brisbourne M. Kendall S.-K. Kufner T. S. Hudson A. M. Smith 2021-07-01 https://doi.org/10.5194/tc-15-3443-2021 https://tc.copernicus.org/articles/15/3443/2021/tc-15-3443-2021.pdf https://doaj.org/article/a64b50a8d88247298799fb2d92f83352 en eng Copernicus Publications doi:10.5194/tc-15-3443-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/3443/2021/tc-15-3443-2021.pdf https://doaj.org/article/a64b50a8d88247298799fb2d92f83352 undefined The Cryosphere, Vol 15, Pp 3443-3458 (2021) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2021 fttriple https://doi.org/10.5194/tc-15-3443-2021 2023-01-22T18:19:40Z Antarctic ice sheet history is imprinted in the structure and fabric of the ice column. At ice rises, the signature of ice flow history is preserved due to the low strain rates inherent at these independent ice flow centres. We present results from a distributed acoustic sensing (DAS) experiment at Skytrain Ice Rise in the Weddell Sea sector of West Antarctica, aimed at delineating the englacial fabric to improve our understanding of ice sheet history in the region. This pilot experiment demonstrates the feasibility of an innovative technique to delineate ice rise structure. Both direct and reflected P- and S-wave energy, as well as surface wave energy, are observed using a range of source offsets, i.e. a walkaway vertical seismic profile, recorded using fibre optic cable. Significant noise, which results from the cable hanging untethered in the borehole, is modelled and suppressed at the processing stage. At greater depth where the cable is suspended in drilling fluid, seismic interval velocities and attenuation are measured. Vertical P-wave velocities are high (VINT=3984±218 m s−1) and consistent with a strong vertical cluster fabric. Seismic attenuation is high (QINT=75±12) and inconsistent with previous observations in ice sheets over this temperature range. The signal level is too low, and the noise level too high, to undertake analysis of englacial fabric variability. However, modelling of P- and S-wave travel times and amplitudes with a range of fabric geometries, combined with these measurements, demonstrates the capacity of the DAS method to discriminate englacial fabric distribution. From this pilot study we make a number of recommendations for future experiments aimed at quantifying englacial fabric to improve our understanding of recent ice sheet history. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet The Cryosphere Weddell Sea West Antarctica Unknown Antarctic Skytrain Ice Rise ENVELOPE(-78.333,-78.333,-79.583,-79.583) Weddell Weddell Sea West Antarctica The Cryosphere 15 7 3443 3458 |
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English |
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geo envir |
spellingShingle |
geo envir A. M. Brisbourne M. Kendall S.-K. Kufner T. S. Hudson A. M. Smith Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica |
topic_facet |
geo envir |
description |
Antarctic ice sheet history is imprinted in the structure and fabric of the ice column. At ice rises, the signature of ice flow history is preserved due to the low strain rates inherent at these independent ice flow centres. We present results from a distributed acoustic sensing (DAS) experiment at Skytrain Ice Rise in the Weddell Sea sector of West Antarctica, aimed at delineating the englacial fabric to improve our understanding of ice sheet history in the region. This pilot experiment demonstrates the feasibility of an innovative technique to delineate ice rise structure. Both direct and reflected P- and S-wave energy, as well as surface wave energy, are observed using a range of source offsets, i.e. a walkaway vertical seismic profile, recorded using fibre optic cable. Significant noise, which results from the cable hanging untethered in the borehole, is modelled and suppressed at the processing stage. At greater depth where the cable is suspended in drilling fluid, seismic interval velocities and attenuation are measured. Vertical P-wave velocities are high (VINT=3984±218 m s−1) and consistent with a strong vertical cluster fabric. Seismic attenuation is high (QINT=75±12) and inconsistent with previous observations in ice sheets over this temperature range. The signal level is too low, and the noise level too high, to undertake analysis of englacial fabric variability. However, modelling of P- and S-wave travel times and amplitudes with a range of fabric geometries, combined with these measurements, demonstrates the capacity of the DAS method to discriminate englacial fabric distribution. From this pilot study we make a number of recommendations for future experiments aimed at quantifying englacial fabric to improve our understanding of recent ice sheet history. |
format |
Article in Journal/Newspaper |
author |
A. M. Brisbourne M. Kendall S.-K. Kufner T. S. Hudson A. M. Smith |
author_facet |
A. M. Brisbourne M. Kendall S.-K. Kufner T. S. Hudson A. M. Smith |
author_sort |
A. M. Brisbourne |
title |
Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica |
title_short |
Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica |
title_full |
Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica |
title_fullStr |
Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica |
title_full_unstemmed |
Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica |
title_sort |
downhole distributed acoustic seismic profiling at skytrain ice rise, west antarctica |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-3443-2021 https://tc.copernicus.org/articles/15/3443/2021/tc-15-3443-2021.pdf https://doaj.org/article/a64b50a8d88247298799fb2d92f83352 |
long_lat |
ENVELOPE(-78.333,-78.333,-79.583,-79.583) |
geographic |
Antarctic Skytrain Ice Rise Weddell Weddell Sea West Antarctica |
geographic_facet |
Antarctic Skytrain Ice Rise Weddell Weddell Sea West Antarctica |
genre |
Antarc* Antarctic Antarctica Ice Sheet The Cryosphere Weddell Sea West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet The Cryosphere Weddell Sea West Antarctica |
op_source |
The Cryosphere, Vol 15, Pp 3443-3458 (2021) |
op_relation |
doi:10.5194/tc-15-3443-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/3443/2021/tc-15-3443-2021.pdf https://doaj.org/article/a64b50a8d88247298799fb2d92f83352 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-15-3443-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
7 |
container_start_page |
3443 |
op_container_end_page |
3458 |
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