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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Cambridge University Press
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ftdoajarticles:oai:doaj.org/article:5579d31274894f3d82efdfda04cb6b6b 2023-05-15T16:20:24+02:00 Active seismic studies in valley glacier settings: strategies and limitations JENNA M. ZECHMANN ADAM D. BOOTH MARTIN TRUFFER ALESSIO GUSMEROLI JASON M. AMUNDSON CHRISTOPHER F. LARSEN 2018-10-01T00:00:00Z https://doi.org/10.1017/jog.2018.69 https://doaj.org/article/5579d31274894f3d82efdfda04cb6b6b EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143018000692/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.69 0022-1430 1727-5652 https://doaj.org/article/5579d31274894f3d82efdfda04cb6b6b Journal of Glaciology, Vol 64, Pp 796-810 (2018) glacial tills glacier geophysics glaciological instruments and methods seismics subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2018 ftdoajarticles https://doi.org/10.1017/jog.2018.69 2023-03-12T01:30:59Z 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 Directory of Open Access Journals: DOAJ Articles Taku ENVELOPE(-133.854,-133.854,59.633,59.633) Journal of Glaciology 64 247 796 810 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
glacial tills glacier geophysics glaciological instruments and methods seismics subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
glacial tills glacier geophysics glaciological instruments and methods seismics subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 JENNA M. ZECHMANN ADAM D. BOOTH MARTIN TRUFFER ALESSIO GUSMEROLI JASON M. AMUNDSON CHRISTOPHER F. LARSEN Active seismic studies in valley glacier settings: strategies and limitations |
topic_facet |
glacial tills glacier geophysics glaciological instruments and methods seismics subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
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 |
JENNA M. ZECHMANN ADAM D. BOOTH MARTIN TRUFFER ALESSIO GUSMEROLI JASON M. AMUNDSON CHRISTOPHER F. LARSEN |
author_facet |
JENNA M. ZECHMANN ADAM D. BOOTH MARTIN TRUFFER ALESSIO GUSMEROLI JASON M. AMUNDSON CHRISTOPHER F. LARSEN |
author_sort |
JENNA M. ZECHMANN |
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://doi.org/10.1017/jog.2018.69 https://doaj.org/article/5579d31274894f3d82efdfda04cb6b6b |
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_source |
Journal of Glaciology, Vol 64, Pp 796-810 (2018) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143018000692/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.69 0022-1430 1727-5652 https://doaj.org/article/5579d31274894f3d82efdfda04cb6b6b |
op_doi |
https://doi.org/10.1017/jog.2018.69 |
container_title |
Journal of Glaciology |
container_volume |
64 |
container_issue |
247 |
container_start_page |
796 |
op_container_end_page |
810 |
_version_ |
1766008319165595648 |