Seismic attenuation in Antarctic firn
We estimate the seismic attenuation of P and S waves in the polar firn and underlying ice by spectral analysis of diving, refracted, and reflected waves from active-source three-component seismic signals obtained in 2010 on the Whillans Ice Stream (WIS), a fast-flowing ice stream in West Antarctica....
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ftcopernicus:oai:publications.copernicus.org:tc109399 2024-02-11T09:58:29+01:00 Seismic attenuation in Antarctic firn Picotti, Stefano Carcione, José M. Pavan, Mauro 2024-01-09 application/pdf https://doi.org/10.5194/tc-18-169-2024 https://tc.copernicus.org/articles/18/169/2024/ eng eng doi:10.5194/tc-18-169-2024 https://tc.copernicus.org/articles/18/169/2024/ eISSN: 1994-0424 Text 2024 ftcopernicus https://doi.org/10.5194/tc-18-169-2024 2024-01-15T17:24:15Z We estimate the seismic attenuation of P and S waves in the polar firn and underlying ice by spectral analysis of diving, refracted, and reflected waves from active-source three-component seismic signals obtained in 2010 on the Whillans Ice Stream (WIS), a fast-flowing ice stream in West Antarctica. The resulting quality factors are then successfully modeled using a rock-physics theory of wave propagation that combines White's mesoscopic attenuation theory of interlayer flow with that of Biot/squirt flow. The first theory describes an equivalent viscoelastic medium consisting of a stack of two alternating thin porous layers, both of which have thicknesses that are much greater than the pore size but smaller than the wavelength. On the other hand, in the so-called Biot/squirt-flow model, there are two loss mechanisms, namely the global Biot flow and the local flow from fluid-filled microcracks (or grain contacts) to the pore space and back, where the former is dominant over the latter. The fluid saturating the pores is assumed to be fluidized snow, defined as a mixture of snow particles and air, such as powder, with a rigidity modulus of zero. Text Antarc* Antarctic Antarctica West Antarctica Whillans Ice Stream Copernicus Publications: E-Journals Antarctic West Antarctica Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) Whillans Ice Stream ENVELOPE(-145.000,-145.000,-83.667,-83.667) The Cryosphere 18 1 169 186 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We estimate the seismic attenuation of P and S waves in the polar firn and underlying ice by spectral analysis of diving, refracted, and reflected waves from active-source three-component seismic signals obtained in 2010 on the Whillans Ice Stream (WIS), a fast-flowing ice stream in West Antarctica. The resulting quality factors are then successfully modeled using a rock-physics theory of wave propagation that combines White's mesoscopic attenuation theory of interlayer flow with that of Biot/squirt flow. The first theory describes an equivalent viscoelastic medium consisting of a stack of two alternating thin porous layers, both of which have thicknesses that are much greater than the pore size but smaller than the wavelength. On the other hand, in the so-called Biot/squirt-flow model, there are two loss mechanisms, namely the global Biot flow and the local flow from fluid-filled microcracks (or grain contacts) to the pore space and back, where the former is dominant over the latter. The fluid saturating the pores is assumed to be fluidized snow, defined as a mixture of snow particles and air, such as powder, with a rigidity modulus of zero. |
format |
Text |
author |
Picotti, Stefano Carcione, José M. Pavan, Mauro |
spellingShingle |
Picotti, Stefano Carcione, José M. Pavan, Mauro Seismic attenuation in Antarctic firn |
author_facet |
Picotti, Stefano Carcione, José M. Pavan, Mauro |
author_sort |
Picotti, Stefano |
title |
Seismic attenuation in Antarctic firn |
title_short |
Seismic attenuation in Antarctic firn |
title_full |
Seismic attenuation in Antarctic firn |
title_fullStr |
Seismic attenuation in Antarctic firn |
title_full_unstemmed |
Seismic attenuation in Antarctic firn |
title_sort |
seismic attenuation in antarctic firn |
publishDate |
2024 |
url |
https://doi.org/10.5194/tc-18-169-2024 https://tc.copernicus.org/articles/18/169/2024/ |
long_lat |
ENVELOPE(-64.250,-64.250,-84.450,-84.450) ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
geographic |
Antarctic West Antarctica Whillans Whillans Ice Stream |
geographic_facet |
Antarctic West Antarctica Whillans Whillans Ice Stream |
genre |
Antarc* Antarctic Antarctica West Antarctica Whillans Ice Stream |
genre_facet |
Antarc* Antarctic Antarctica West Antarctica Whillans Ice Stream |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-18-169-2024 https://tc.copernicus.org/articles/18/169/2024/ |
op_doi |
https://doi.org/10.5194/tc-18-169-2024 |
container_title |
The Cryosphere |
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18 |
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1 |
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169 |
op_container_end_page |
186 |
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1790594136412258304 |