Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica
We present seismic measurements of the firn column at Korff Ice Rise, West Antarctica, including measurements of compressional-wave velocity and attenuation. We describe a modified spectral-ratio method of measuring the seismic quality factor (Q) based on analysis of diving waves, which, combined wi...
Published in: | Journal of Glaciology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press
2023
|
Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/536191/ https://nora.nerc.ac.uk/id/eprint/536191/1/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica.pdf https://www.cambridge.org/core/journals/journal-of-glaciology/article/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica/AC9A5721039171C29B5A88E914D6487B |
id |
ftnerc:oai:nora.nerc.ac.uk:536191 |
---|---|
record_format |
openpolar |
spelling |
ftnerc:oai:nora.nerc.ac.uk:536191 2023-12-03T10:13:26+01:00 Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica Agnew, Ronan S. Clark, Roger A. Booth, Adam D. Brisbourne, Alex M. Smith, Andrew M. 2023-10-26 text http://nora.nerc.ac.uk/id/eprint/536191/ https://nora.nerc.ac.uk/id/eprint/536191/1/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica.pdf https://www.cambridge.org/core/journals/journal-of-glaciology/article/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica/AC9A5721039171C29B5A88E914D6487B en eng Cambridge University Press https://nora.nerc.ac.uk/id/eprint/536191/1/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica.pdf Agnew, Ronan S. orcid:0009-0000-3609-6815 Clark, Roger A.; Booth, Adam D.; Brisbourne, Alex M. orcid:0000-0002-9887-7120 Smith, Andrew M. orcid:0000-0001-8577-482X . 2023 Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica. Journal of Glaciology. 12, pp. https://doi.org/10.1017/jog.2023.82 <https://doi.org/10.1017/jog.2023.82> cc_by_4 Publication - Article PeerReviewed 2023 ftnerc https://doi.org/10.1017/jog.2023.82 2023-11-03T00:03:09Z We present seismic measurements of the firn column at Korff Ice Rise, West Antarctica, including measurements of compressional-wave velocity and attenuation. We describe a modified spectral-ratio method of measuring the seismic quality factor (Q) based on analysis of diving waves, which, combined with a stochastic method of error propagation, enables us to characterise the attenuative structure of firn in greater detail than has previously been possible. Q increases from 56 ± 23 in the uppermost 12 m to 570 ± 450 between 55 and 77 m depth. We corroborate our method with consistent measurements obtained via primary reflection, multiple, source ghost, and critically refracted waves. Using the primary reflection and its ghost, we find Q = 53 ± 20 in the uppermost 20 m of firn. From the critical refraction, we find Q = 640 ± 400 at 90 m depth. Our method aids the understanding of the seismic structure of firn and benefits characterisation of deeper glaciological targets, providing an alternative means of correcting seismic reflection amplitudes in cases where conventional methods of Q correction may be impossible. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal Journal of Glaciology West Antarctica Natural Environment Research Council: NERC Open Research Archive West Antarctica Korff Ice Rise ENVELOPE(-70.000,-70.000,-79.000,-79.000) Journal of Glaciology 1 12 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
We present seismic measurements of the firn column at Korff Ice Rise, West Antarctica, including measurements of compressional-wave velocity and attenuation. We describe a modified spectral-ratio method of measuring the seismic quality factor (Q) based on analysis of diving waves, which, combined with a stochastic method of error propagation, enables us to characterise the attenuative structure of firn in greater detail than has previously been possible. Q increases from 56 ± 23 in the uppermost 12 m to 570 ± 450 between 55 and 77 m depth. We corroborate our method with consistent measurements obtained via primary reflection, multiple, source ghost, and critically refracted waves. Using the primary reflection and its ghost, we find Q = 53 ± 20 in the uppermost 20 m of firn. From the critical refraction, we find Q = 640 ± 400 at 90 m depth. Our method aids the understanding of the seismic structure of firn and benefits characterisation of deeper glaciological targets, providing an alternative means of correcting seismic reflection amplitudes in cases where conventional methods of Q correction may be impossible. |
format |
Article in Journal/Newspaper |
author |
Agnew, Ronan S. Clark, Roger A. Booth, Adam D. Brisbourne, Alex M. Smith, Andrew M. |
spellingShingle |
Agnew, Ronan S. Clark, Roger A. Booth, Adam D. Brisbourne, Alex M. Smith, Andrew M. Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica |
author_facet |
Agnew, Ronan S. Clark, Roger A. Booth, Adam D. Brisbourne, Alex M. Smith, Andrew M. |
author_sort |
Agnew, Ronan S. |
title |
Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica |
title_short |
Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica |
title_full |
Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica |
title_fullStr |
Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica |
title_full_unstemmed |
Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica |
title_sort |
measuring seismic attenuation in polar firn: method and application to korff ice rise, west antarctica |
publisher |
Cambridge University Press |
publishDate |
2023 |
url |
http://nora.nerc.ac.uk/id/eprint/536191/ https://nora.nerc.ac.uk/id/eprint/536191/1/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica.pdf https://www.cambridge.org/core/journals/journal-of-glaciology/article/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica/AC9A5721039171C29B5A88E914D6487B |
long_lat |
ENVELOPE(-70.000,-70.000,-79.000,-79.000) |
geographic |
West Antarctica Korff Ice Rise |
geographic_facet |
West Antarctica Korff Ice Rise |
genre |
Antarc* Antarctica Antarctica Journal Journal of Glaciology West Antarctica |
genre_facet |
Antarc* Antarctica Antarctica Journal Journal of Glaciology West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/536191/1/measuring-seismic-attenuation-in-polar-firn-method-and-application-to-korff-ice-rise-west-antarctica.pdf Agnew, Ronan S. orcid:0009-0000-3609-6815 Clark, Roger A.; Booth, Adam D.; Brisbourne, Alex M. orcid:0000-0002-9887-7120 Smith, Andrew M. orcid:0000-0001-8577-482X . 2023 Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica. Journal of Glaciology. 12, pp. https://doi.org/10.1017/jog.2023.82 <https://doi.org/10.1017/jog.2023.82> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1017/jog.2023.82 |
container_title |
Journal of Glaciology |
container_start_page |
1 |
op_container_end_page |
12 |
_version_ |
1784260195035119616 |