Active seismic studies in valley glacier settings: strategies and limitations
Subglacial tills play an important role in glacier dynamics but are difficult to characterize in situ. Amplitude Variation with Angle (AVA) analysis of seismic reflection data can distinguish between stiff tills and deformable tills. However, AVA analysis in mountain glacier environments can be prob...
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ftleedsuniv:oai:eprints.whiterose.ac.uk:137704 2023-05-15T16:20:24+02:00 Active seismic studies in valley glacier settings: strategies and limitations Zechmann, JM Booth, AD Truffer, M Gusmeroli, A Amundson, JM Larsen, CF 2018-10 text https://eprints.whiterose.ac.uk/137704/ https://eprints.whiterose.ac.uk/137704/7/active_seismic_studies_in_valley_glacier_settings_strategies_and_limitations.pdf en eng Cambridge University Press https://eprints.whiterose.ac.uk/137704/7/active_seismic_studies_in_valley_glacier_settings_strategies_and_limitations.pdf Zechmann, JM, Booth, AD orcid.org/0000-0002-8166-9608 , Truffer, M et al. (3 more authors) (2018) Active seismic studies in valley glacier settings: strategies and limitations. Journal of Glaciology, 64 (247). pp. 796-810. ISSN 0022-1430 cc_by_4 CC-BY Article NonPeerReviewed 2018 ftleedsuniv 2023-01-30T22:11:58Z Subglacial tills play an important role in glacier dynamics but are difficult to characterize in situ. Amplitude Variation with Angle (AVA) analysis of seismic reflection data can distinguish between stiff tills and deformable tills. However, AVA analysis in mountain glacier environments can be problematic: reflections can be obscured by Rayleigh wave energy scattered from crevasses, and complex basal topography can impede the location of reflection points in 2-D acquisitions. We use a forward model to produce challenging synthetic seismic records in order to test the efficacy of AVA in crevassed and geometrically complex environments. We find that we can distinguish subglacial till types in moderately crevassed environments, where ‘moderate’ depends on crevasse spacing and orientation. The forward model serves as a planning tool, as it can predict AVA success or failure based on characteristics of the study glacier. Applying lessons from the forward model, we perform AVA on a seismic dataset collected from Taku Glacier in Southeast Alaska in March 2016. Taku Glacier is a valley glacier thought to overlay thick sediment deposits. A near-offset polarity reversal confirms that the tills are deformable. Article in Journal/Newspaper glacier Journal of Glaciology Alaska White Rose Research Online (Universities of Leeds, Sheffield & York) Taku ENVELOPE(-133.854,-133.854,59.633,59.633) |
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Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
Subglacial tills play an important role in glacier dynamics but are difficult to characterize in situ. Amplitude Variation with Angle (AVA) analysis of seismic reflection data can distinguish between stiff tills and deformable tills. However, AVA analysis in mountain glacier environments can be problematic: reflections can be obscured by Rayleigh wave energy scattered from crevasses, and complex basal topography can impede the location of reflection points in 2-D acquisitions. We use a forward model to produce challenging synthetic seismic records in order to test the efficacy of AVA in crevassed and geometrically complex environments. We find that we can distinguish subglacial till types in moderately crevassed environments, where ‘moderate’ depends on crevasse spacing and orientation. The forward model serves as a planning tool, as it can predict AVA success or failure based on characteristics of the study glacier. Applying lessons from the forward model, we perform AVA on a seismic dataset collected from Taku Glacier in Southeast Alaska in March 2016. Taku Glacier is a valley glacier thought to overlay thick sediment deposits. A near-offset polarity reversal confirms that the tills are deformable. |
format |
Article in Journal/Newspaper |
author |
Zechmann, JM Booth, AD Truffer, M Gusmeroli, A Amundson, JM Larsen, CF |
spellingShingle |
Zechmann, JM Booth, AD Truffer, M Gusmeroli, A Amundson, JM Larsen, CF Active seismic studies in valley glacier settings: strategies and limitations |
author_facet |
Zechmann, JM Booth, AD Truffer, M Gusmeroli, A Amundson, JM Larsen, CF |
author_sort |
Zechmann, JM |
title |
Active seismic studies in valley glacier settings: strategies and limitations |
title_short |
Active seismic studies in valley glacier settings: strategies and limitations |
title_full |
Active seismic studies in valley glacier settings: strategies and limitations |
title_fullStr |
Active seismic studies in valley glacier settings: strategies and limitations |
title_full_unstemmed |
Active seismic studies in valley glacier settings: strategies and limitations |
title_sort |
active seismic studies in valley glacier settings: strategies and limitations |
publisher |
Cambridge University Press |
publishDate |
2018 |
url |
https://eprints.whiterose.ac.uk/137704/ https://eprints.whiterose.ac.uk/137704/7/active_seismic_studies_in_valley_glacier_settings_strategies_and_limitations.pdf |
long_lat |
ENVELOPE(-133.854,-133.854,59.633,59.633) |
geographic |
Taku |
geographic_facet |
Taku |
genre |
glacier Journal of Glaciology Alaska |
genre_facet |
glacier Journal of Glaciology Alaska |
op_relation |
https://eprints.whiterose.ac.uk/137704/7/active_seismic_studies_in_valley_glacier_settings_strategies_and_limitations.pdf Zechmann, JM, Booth, AD orcid.org/0000-0002-8166-9608 , Truffer, M et al. (3 more authors) (2018) Active seismic studies in valley glacier settings: strategies and limitations. Journal of Glaciology, 64 (247). pp. 796-810. ISSN 0022-1430 |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
_version_ |
1766008316806299648 |