On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring

Ambient noise seismology has revolutionized seismic characterization of the Earth's crust from local to global scales. The estimate of Green's function (GF) between two receivers, representing the impulse response of elastic media, can be reconstructed via cross-correlation of the ambient...

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Published in:The Cryosphere
Main Authors: A. Sergeant, M. Chmiel, F. Lindner, F. Walter, P. Roux, J. Chaput, F. Gimbert, A. Mordret
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2020
Subjects:
Online Access:https://doi.org/10.5194/tc-14-1139-2020
https://doaj.org/article/30342200b31445c2b41d1679d2adcbbf
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spelling ftdoajarticles:oai:doaj.org/article:30342200b31445c2b41d1679d2adcbbf 2023-05-15T16:21:24+02:00 On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring A. Sergeant M. Chmiel F. Lindner F. Walter P. Roux J. Chaput F. Gimbert A. Mordret 2020-04-01T00:00:00Z https://doi.org/10.5194/tc-14-1139-2020 https://doaj.org/article/30342200b31445c2b41d1679d2adcbbf EN eng Copernicus Publications https://www.the-cryosphere.net/14/1139/2020/tc-14-1139-2020.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-14-1139-2020 1994-0416 1994-0424 https://doaj.org/article/30342200b31445c2b41d1679d2adcbbf The Cryosphere, Vol 14, Pp 1139-1171 (2020) Environmental sciences GE1-350 Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.5194/tc-14-1139-2020 2022-12-31T04:35:03Z Ambient noise seismology has revolutionized seismic characterization of the Earth's crust from local to global scales. The estimate of Green's function (GF) between two receivers, representing the impulse response of elastic media, can be reconstructed via cross-correlation of the ambient noise seismograms. A homogenized wave field illuminating the propagation medium in all directions is a prerequisite for obtaining an accurate GF. For seismic data recorded on glaciers, this condition imposes strong limitations on GF convergence because of minimal seismic scattering in homogeneous ice and limitations in network coverage. We address this difficulty by investigating three patterns of seismic wave fields: a favorable distribution of icequakes and noise sources recorded on a dense array of 98 sensors on Glacier d'Argentière (France), a dominant noise source constituted by a moulin within a smaller seismic array on the Greenland Ice Sheet, and crevasse-generated scattering at Gornergletscher (Switzerland). In Glacier d'Argentière, surface melt routing through englacial channels produces turbulent water flow, creating sustained ambient seismic sources and thus favorable conditions for GF estimates. Analysis of the cross-correlation functions reveals non-equally distributed noise sources outside and within the recording network. The dense sampling of sensors allows for spatial averaging and accurate GF estimates when stacked on lines of receivers. The averaged GFs contain high-frequency ( >30 Hz ) direct and refracted P waves in addition to the fundamental mode of dispersive Rayleigh waves above 1 Hz . From seismic velocity measurements, we invert bed properties and depth profiles and map seismic anisotropy, which is likely introduced by crevassing. In Greenland, we employ an advanced preprocessing scheme which includes match-field processing and eigenspectral equalization of the cross spectra to remove the moulin source signature and reduce the effect of inhomogeneous wave fields on the GFs. At Gornergletscher, ... Article in Journal/Newspaper glacier Greenland Ice Sheet The Cryosphere Directory of Open Access Journals: DOAJ Articles Greenland The Cryosphere 14 3 1139 1171
institution Open Polar
collection Directory of Open Access Journals: DOAJ Articles
op_collection_id ftdoajarticles
language English
topic Environmental sciences
GE1-350
Geology
QE1-996.5
spellingShingle Environmental sciences
GE1-350
Geology
QE1-996.5
A. Sergeant
M. Chmiel
F. Lindner
F. Walter
P. Roux
J. Chaput
F. Gimbert
A. Mordret
On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
topic_facet Environmental sciences
GE1-350
Geology
QE1-996.5
description Ambient noise seismology has revolutionized seismic characterization of the Earth's crust from local to global scales. The estimate of Green's function (GF) between two receivers, representing the impulse response of elastic media, can be reconstructed via cross-correlation of the ambient noise seismograms. A homogenized wave field illuminating the propagation medium in all directions is a prerequisite for obtaining an accurate GF. For seismic data recorded on glaciers, this condition imposes strong limitations on GF convergence because of minimal seismic scattering in homogeneous ice and limitations in network coverage. We address this difficulty by investigating three patterns of seismic wave fields: a favorable distribution of icequakes and noise sources recorded on a dense array of 98 sensors on Glacier d'Argentière (France), a dominant noise source constituted by a moulin within a smaller seismic array on the Greenland Ice Sheet, and crevasse-generated scattering at Gornergletscher (Switzerland). In Glacier d'Argentière, surface melt routing through englacial channels produces turbulent water flow, creating sustained ambient seismic sources and thus favorable conditions for GF estimates. Analysis of the cross-correlation functions reveals non-equally distributed noise sources outside and within the recording network. The dense sampling of sensors allows for spatial averaging and accurate GF estimates when stacked on lines of receivers. The averaged GFs contain high-frequency ( >30 Hz ) direct and refracted P waves in addition to the fundamental mode of dispersive Rayleigh waves above 1 Hz . From seismic velocity measurements, we invert bed properties and depth profiles and map seismic anisotropy, which is likely introduced by crevassing. In Greenland, we employ an advanced preprocessing scheme which includes match-field processing and eigenspectral equalization of the cross spectra to remove the moulin source signature and reduce the effect of inhomogeneous wave fields on the GFs. At Gornergletscher, ...
format Article in Journal/Newspaper
author A. Sergeant
M. Chmiel
F. Lindner
F. Walter
P. Roux
J. Chaput
F. Gimbert
A. Mordret
author_facet A. Sergeant
M. Chmiel
F. Lindner
F. Walter
P. Roux
J. Chaput
F. Gimbert
A. Mordret
author_sort A. Sergeant
title On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
title_short On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
title_full On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
title_fullStr On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
title_full_unstemmed On the Green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
title_sort on the green's function emergence from interferometry of seismic wave fields generated in high-melt glaciers: implications for passive imaging and monitoring
publisher Copernicus Publications
publishDate 2020
url https://doi.org/10.5194/tc-14-1139-2020
https://doaj.org/article/30342200b31445c2b41d1679d2adcbbf
geographic Greenland
geographic_facet Greenland
genre glacier
Greenland
Ice Sheet
The Cryosphere
genre_facet glacier
Greenland
Ice Sheet
The Cryosphere
op_source The Cryosphere, Vol 14, Pp 1139-1171 (2020)
op_relation https://www.the-cryosphere.net/14/1139/2020/tc-14-1139-2020.pdf
https://doaj.org/toc/1994-0416
https://doaj.org/toc/1994-0424
doi:10.5194/tc-14-1139-2020
1994-0416
1994-0424
https://doaj.org/article/30342200b31445c2b41d1679d2adcbbf
op_doi https://doi.org/10.5194/tc-14-1139-2020
container_title The Cryosphere
container_volume 14
container_issue 3
container_start_page 1139
op_container_end_page 1171
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