Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves

International audience The attenuation of seismic shear waves in the mantle beneath the eastern Australian and Antarctic plates is analyzed using a large data set of multiple ScSn waves, reflected n times at the core-mantle boundary and (n-1) times at the surface. The data are the transverse compone...

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Main Authors: Souriau, Annie, Rivera, Luis, Maggi, Alessia, Lévêque, J.J.
Other Authors: Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Sismologie (IPGS) (IPGS-Sismologie), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2012
Subjects:
Online Access:https://hal.science/hal-00686804
https://hal.science/hal-00686804/document
https://hal.science/hal-00686804/file/190-1-569-1.pdf
id ftutoulouse3hal:oai:HAL:hal-00686804v1
record_format openpolar
institution Open Polar
collection Université Toulouse III - Paul Sabatier: HAL-UPS
op_collection_id ftutoulouse3hal
language English
topic [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
[SDE.MCG]Environmental Sciences/Global Changes
spellingShingle [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
[SDE.MCG]Environmental Sciences/Global Changes
Souriau, Annie
Rivera, Luis
Maggi, Alessia
Lévêque, J.J.
Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves
topic_facet [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
[SDE.MCG]Environmental Sciences/Global Changes
description International audience The attenuation of seismic shear waves in the mantle beneath the eastern Australian and Antarctic plates is analyzed using a large data set of multiple ScSn waves, reflected n times at the core-mantle boundary and (n-1) times at the surface. The data are the transverse components of deep earthquakes from the subduction zones north and east of Australia, recorded at stations in Antarctica, Australia, Indonesia, New Caledonia and New Zealand. The data are filtered with narrow band-pass filters at 5 frequencies in the range 0.013-0.040 Hz. The ScSn+1/ScSn amplitude ratios of successive ScS phases are compared to the ratios computed for synthetic seismograms for the same paths and same focal mechanisms, in order to eliminate the effects of source radiation and geometric attenuation. The synthetic seismograms are computed from a summation of toroidal modes for the 1-D reference model PREM (Dziewonski & Anderson 1981). The observed to computed spectral ratios appear consistent for similar paths. They reveal that the attenuation is not frequency dependent, that the contribution of scattering to attenuation is low, and that the PREM model is a valuable reference model for the study region at the considered frequencies. An inversion of the data at 0.026 Hz is performed to retrieve the quality factor Q in the upper mantle, in regions defined using a priori constraints inferred from seismic shear velocities. Q-values close to those of PREM are found beneath the Australian and Antarctic cratons, lower values beneath the Eastern Australian Phanerozoic margin, and very low values beneath the oceanic region between Australia and Antarctica, where ridges and a triple junction are present. The Australian-Antarctic Discordance along the South-Indian ridge appears as an exception with a Q-value close to those of stable continents. The highest Q-values are found beneath the subduction zones, a feature which is not apparent in global attenuation models possibly because of its narrow lateral extension, ...
author2 Institut de recherche en astrophysique et planétologie (IRAP)
Université Toulouse III - Paul Sabatier (UT3)
Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP)
Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3)
Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)
Sismologie (IPGS) (IPGS-Sismologie)
Institut de physique du globe de Strasbourg (IPGS)
Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
format Article in Journal/Newspaper
author Souriau, Annie
Rivera, Luis
Maggi, Alessia
Lévêque, J.J.
author_facet Souriau, Annie
Rivera, Luis
Maggi, Alessia
Lévêque, J.J.
author_sort Souriau, Annie
title Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves
title_short Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves
title_full Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves
title_fullStr Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves
title_full_unstemmed Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves
title_sort seismic attenuation in the eastern australian and antarctic plates from multiple scs waves
publisher HAL CCSD
publishDate 2012
url https://hal.science/hal-00686804
https://hal.science/hal-00686804/document
https://hal.science/hal-00686804/file/190-1-569-1.pdf
genre Antarc*
Antarctic
Antarctica
genre_facet Antarc*
Antarctic
Antarctica
op_source ISSN: 0956-540X
EISSN: 1365-246X
Geophysical Journal International
https://hal.science/hal-00686804
Geophysical Journal International, 2012, pp.GJI-11-0783.R1
op_relation hal-00686804
https://hal.science/hal-00686804
https://hal.science/hal-00686804/document
https://hal.science/hal-00686804/file/190-1-569-1.pdf
op_rights http://creativecommons.org/licenses/by/
info:eu-repo/semantics/OpenAccess
_version_ 1810491497322119168
spelling ftutoulouse3hal:oai:HAL:hal-00686804v1 2024-09-15T17:44:08+00:00 Seismic attenuation in the eastern Australian and Antarctic plates from multiple ScS waves Souriau, Annie Rivera, Luis Maggi, Alessia Lévêque, J.J. Institut de recherche en astrophysique et planétologie (IRAP) Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) Sismologie (IPGS) (IPGS-Sismologie) Institut de physique du globe de Strasbourg (IPGS) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) 2012 https://hal.science/hal-00686804 https://hal.science/hal-00686804/document https://hal.science/hal-00686804/file/190-1-569-1.pdf en eng HAL CCSD Oxford University Press (OUP) hal-00686804 https://hal.science/hal-00686804 https://hal.science/hal-00686804/document https://hal.science/hal-00686804/file/190-1-569-1.pdf http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 0956-540X EISSN: 1365-246X Geophysical Journal International https://hal.science/hal-00686804 Geophysical Journal International, 2012, pp.GJI-11-0783.R1 [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2012 ftutoulouse3hal 2024-06-25T00:11:19Z International audience The attenuation of seismic shear waves in the mantle beneath the eastern Australian and Antarctic plates is analyzed using a large data set of multiple ScSn waves, reflected n times at the core-mantle boundary and (n-1) times at the surface. The data are the transverse components of deep earthquakes from the subduction zones north and east of Australia, recorded at stations in Antarctica, Australia, Indonesia, New Caledonia and New Zealand. The data are filtered with narrow band-pass filters at 5 frequencies in the range 0.013-0.040 Hz. The ScSn+1/ScSn amplitude ratios of successive ScS phases are compared to the ratios computed for synthetic seismograms for the same paths and same focal mechanisms, in order to eliminate the effects of source radiation and geometric attenuation. The synthetic seismograms are computed from a summation of toroidal modes for the 1-D reference model PREM (Dziewonski & Anderson 1981). The observed to computed spectral ratios appear consistent for similar paths. They reveal that the attenuation is not frequency dependent, that the contribution of scattering to attenuation is low, and that the PREM model is a valuable reference model for the study region at the considered frequencies. An inversion of the data at 0.026 Hz is performed to retrieve the quality factor Q in the upper mantle, in regions defined using a priori constraints inferred from seismic shear velocities. Q-values close to those of PREM are found beneath the Australian and Antarctic cratons, lower values beneath the Eastern Australian Phanerozoic margin, and very low values beneath the oceanic region between Australia and Antarctica, where ridges and a triple junction are present. The Australian-Antarctic Discordance along the South-Indian ridge appears as an exception with a Q-value close to those of stable continents. The highest Q-values are found beneath the subduction zones, a feature which is not apparent in global attenuation models possibly because of its narrow lateral extension, ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Université Toulouse III - Paul Sabatier: HAL-UPS