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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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/397735 2023-08-20T04:10:08+02:00 Glaciohydraulic seismic tremors on an Alpine glacier Lindner, Fabian Walter, Fabian Laske, Gabi Gimbert, Florent 2020 application/application/pdf https://hdl.handle.net/20.500.11850/397735 https://doi.org/10.3929/ethz-b-000397735 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-14-287-2020 info:eu-repo/semantics/altIdentifier/wos/000510383000001 info:eu-repo/grantAgreement/SNF/SNF-Förderungsprofessuren Stufe 2/157551 http://hdl.handle.net/20.500.11850/397735 doi:10.3929/ethz-b-000397735 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International The Cryosphere, 14 (1) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2020 ftethz https://doi.org/20.500.11850/39773510.3929/ethz-b-00039773510.5194/tc-14-287-2020 2023-07-30T23:51:39Z 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. ISSN:1994-0416 ISSN:1994-0424 Article in Journal/Newspaper The Cryosphere ETH Zürich Research Collection Marginal Lake ENVELOPE(163.500,163.500,-74.600,-74.600) |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
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. ISSN:1994-0416 ISSN:1994-0424 |
format |
Article in Journal/Newspaper |
author |
Lindner, Fabian Walter, Fabian Laske, Gabi Gimbert, Florent |
spellingShingle |
Lindner, Fabian Walter, Fabian Laske, Gabi Gimbert, Florent Glaciohydraulic seismic tremors on an Alpine glacier |
author_facet |
Lindner, Fabian Walter, Fabian Laske, Gabi Gimbert, Florent |
author_sort |
Lindner, Fabian |
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 |
publishDate |
2020 |
url |
https://hdl.handle.net/20.500.11850/397735 https://doi.org/10.3929/ethz-b-000397735 |
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, 14 (1) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-14-287-2020 info:eu-repo/semantics/altIdentifier/wos/000510383000001 info:eu-repo/grantAgreement/SNF/SNF-Förderungsprofessuren Stufe 2/157551 http://hdl.handle.net/20.500.11850/397735 doi:10.3929/ethz-b-000397735 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/39773510.3929/ethz-b-00039773510.5194/tc-14-287-2020 |
_version_ |
1774724107420565504 |