Agnew, R.S., Clark, R.A. orcid.org/0000-0002-3508-8183, Booth, A.D. orcid.org/0000-0002-8166-9608 et al. (2 more authors) (2023) Measuring seismic attenuation in polar firn: method and application to Korff Ice Rise, West Antarctica. Journal of Glaciology. ISSN 0022-1430
Abstract
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.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s), 2023. Published by Cambridge University Press on behalf of The International Glaciological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited. |
Keywords: | Glacier geophysics; glaciological instruments and methods; polar firn; seismics |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Jul 2024 15:43 |
Last Modified: | 04 Jul 2024 15:43 |
Status: | Published online |
Publisher: | Cambridge University Press (CUP) |
Identification Number: | 10.1017/jog.2023.82 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:213815 |