Glaciohydraulic seismic tremors on an Alpine glacier
Hydraulic processes impact viscous and brittle ice deformation. Water-driven fracturing as well as turbulent water flow within and beneath glaciers radiate seismic waves which provide insights into otherwise hard-to-access englacial and subglacial environments. In this study, we analyze glaciohydrau...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:a3026e51c05b48e79ac6cdb35094f861 2023-05-15T18:32:16+02:00 Glaciohydraulic seismic tremors on an Alpine glacier F. Lindner F. Walter G. Laske F. Gimbert 2020-01-01 https://doi.org/10.5194/tc-14-287-2020 https://www.the-cryosphere.net/14/287/2020/tc-14-287-2020.pdf https://doaj.org/article/a3026e51c05b48e79ac6cdb35094f861 en eng Copernicus Publications doi:10.5194/tc-14-287-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/287/2020/tc-14-287-2020.pdf https://doaj.org/article/a3026e51c05b48e79ac6cdb35094f861 undefined The Cryosphere, Vol 14, Pp 287-308 (2020) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/tc-14-287-2020 2023-01-22T19:30:40Z Hydraulic processes impact viscous and brittle ice deformation. Water-driven fracturing as well as turbulent water flow within and beneath glaciers radiate seismic waves which provide insights into otherwise hard-to-access englacial and subglacial environments. In this study, we analyze glaciohydraulic tremors recorded by four seismic arrays installed in different parts of Glacier de la Plaine Morte, Switzerland. Data were recorded during the 2016 melt season including the sudden subglacial drainage of an ice-marginal lake. Together with our seismic data, discharge, lake level, and ice flow measurements provide constraints on glacier hydraulics. We find that the tremors are generated by subglacial water flow, in moulins, and by icequake bursts. The dominating process can vary on sub-kilometer and sub-daily scales. Consistent with field observations, continuous source tracking via matched-field processing suggests a gradual up-glacier progression of an efficient drainage system as the melt season progresses. The ice-marginal lake likely connects to this drainage system via hydrofracturing, which is indicated by sustained icequake signals emitted from the proximity of the lake basin and starting roughly 24 h prior to the lake drainage. To estimate the hydraulics associated with the drainage, we use tremor–discharge scaling relationships. Our analysis suggests a pressurization of the subglacial environment at the drainage onset, followed by an increase in the hydraulic radii of the conduits and a subsequent decrease in the subglacial water pressure as the capacity of the drainage system increases. The pressurization is in phase with the drop in the lake level, and its retrieved maximum coincides with ice uplift measured via GPS. Our results highlight the use of cryo-seismology for monitoring glacier hydraulics. Article in Journal/Newspaper The Cryosphere Unknown Marginal Lake ENVELOPE(163.500,163.500,-74.600,-74.600) The Cryosphere 14 1 287 308 |
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English |
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geo envir F. Lindner F. Walter G. Laske F. Gimbert Glaciohydraulic seismic tremors on an Alpine glacier |
topic_facet |
geo envir |
description |
Hydraulic processes impact viscous and brittle ice deformation. Water-driven fracturing as well as turbulent water flow within and beneath glaciers radiate seismic waves which provide insights into otherwise hard-to-access englacial and subglacial environments. In this study, we analyze glaciohydraulic tremors recorded by four seismic arrays installed in different parts of Glacier de la Plaine Morte, Switzerland. Data were recorded during the 2016 melt season including the sudden subglacial drainage of an ice-marginal lake. Together with our seismic data, discharge, lake level, and ice flow measurements provide constraints on glacier hydraulics. We find that the tremors are generated by subglacial water flow, in moulins, and by icequake bursts. The dominating process can vary on sub-kilometer and sub-daily scales. Consistent with field observations, continuous source tracking via matched-field processing suggests a gradual up-glacier progression of an efficient drainage system as the melt season progresses. The ice-marginal lake likely connects to this drainage system via hydrofracturing, which is indicated by sustained icequake signals emitted from the proximity of the lake basin and starting roughly 24 h prior to the lake drainage. To estimate the hydraulics associated with the drainage, we use tremor–discharge scaling relationships. Our analysis suggests a pressurization of the subglacial environment at the drainage onset, followed by an increase in the hydraulic radii of the conduits and a subsequent decrease in the subglacial water pressure as the capacity of the drainage system increases. The pressurization is in phase with the drop in the lake level, and its retrieved maximum coincides with ice uplift measured via GPS. Our results highlight the use of cryo-seismology for monitoring glacier hydraulics. |
format |
Article in Journal/Newspaper |
author |
F. Lindner F. Walter G. Laske F. Gimbert |
author_facet |
F. Lindner F. Walter G. Laske F. Gimbert |
author_sort |
F. Lindner |
title |
Glaciohydraulic seismic tremors on an Alpine glacier |
title_short |
Glaciohydraulic seismic tremors on an Alpine glacier |
title_full |
Glaciohydraulic seismic tremors on an Alpine glacier |
title_fullStr |
Glaciohydraulic seismic tremors on an Alpine glacier |
title_full_unstemmed |
Glaciohydraulic seismic tremors on an Alpine glacier |
title_sort |
glaciohydraulic seismic tremors on an alpine glacier |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-287-2020 https://www.the-cryosphere.net/14/287/2020/tc-14-287-2020.pdf https://doaj.org/article/a3026e51c05b48e79ac6cdb35094f861 |
long_lat |
ENVELOPE(163.500,163.500,-74.600,-74.600) |
geographic |
Marginal Lake |
geographic_facet |
Marginal Lake |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 14, Pp 287-308 (2020) |
op_relation |
doi:10.5194/tc-14-287-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/287/2020/tc-14-287-2020.pdf https://doaj.org/article/a3026e51c05b48e79ac6cdb35094f861 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-14-287-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
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1 |
container_start_page |
287 |
op_container_end_page |
308 |
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