Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield
Ambient noise tomography (ANT) is widely used to image strong velocity variations within the upper crust . Using careful processing, we obtained a 3-D model of shear velocities in the upper crust beneath northern Finland, where the lateral velocity variations are less than 3%. As part of the tomogra...
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ftunivsavoie:oai:HAL:hal-00721895v1 2024-04-28T08:32:24+00:00 Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield Poli, Piero Campillo, M. Pedersen, Helle A. Institut des Sciences de la Terre (ISTerre) Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement IRD : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS) 2012-05-03 https://hal.science/hal-00721895 https://hal.science/hal-00721895/document https://hal.science/hal-00721895/file/Complete_Manuscript.pdf en eng HAL CCSD hal-00721895 https://hal.science/hal-00721895 https://hal.science/hal-00721895/document https://hal.science/hal-00721895/file/Complete_Manuscript.pdf info:eu-repo/semantics/OpenAccess https://hal.science/hal-00721895 2012 [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/report Reports 2012 ftunivsavoie 2024-04-11T00:16:41Z Ambient noise tomography (ANT) is widely used to image strong velocity variations within the upper crust . Using careful processing, we obtained a 3-D model of shear velocities in the upper crust beneath northern Finland, where the lateral velocity variations are less than 3%. As part of the tomography, the noise field is analysed. It is strongly heterogeneous but the signal to noise ratio is sufficient to obtain stable dispersion curves for all profile azimuths. Our results show that the directions of dominant noise sources of Rayleigh and Love waves are the same, but the amplitude distribution with azimuth is different for the two types of waves. More intriguingly, the high frequency Love waves are dominated by a mixture of higher modes rather than the fundamental mode. The reconstructed 3-D model shows the Lapland Granulite Belt as a high velocity body with a limit at surface in excellent agreement with geological observations at surface. Following this interface at depth, our results are compatible with previous studies suggesting an archean north oriented subduction. Report Northern Finland Lapland Université Savoie Mont Blanc: HAL |
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Open Polar |
collection |
Université Savoie Mont Blanc: HAL |
op_collection_id |
ftunivsavoie |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Poli, Piero Campillo, M. Pedersen, Helle A. Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
Ambient noise tomography (ANT) is widely used to image strong velocity variations within the upper crust . Using careful processing, we obtained a 3-D model of shear velocities in the upper crust beneath northern Finland, where the lateral velocity variations are less than 3%. As part of the tomography, the noise field is analysed. It is strongly heterogeneous but the signal to noise ratio is sufficient to obtain stable dispersion curves for all profile azimuths. Our results show that the directions of dominant noise sources of Rayleigh and Love waves are the same, but the amplitude distribution with azimuth is different for the two types of waves. More intriguingly, the high frequency Love waves are dominated by a mixture of higher modes rather than the fundamental mode. The reconstructed 3-D model shows the Lapland Granulite Belt as a high velocity body with a limit at surface in excellent agreement with geological observations at surface. Following this interface at depth, our results are compatible with previous studies suggesting an archean north oriented subduction. |
author2 |
Institut des Sciences de la Terre (ISTerre) Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement IRD : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS) |
format |
Report |
author |
Poli, Piero Campillo, M. Pedersen, Helle A. |
author_facet |
Poli, Piero Campillo, M. Pedersen, Helle A. |
author_sort |
Poli, Piero |
title |
Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield |
title_short |
Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield |
title_full |
Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield |
title_fullStr |
Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield |
title_full_unstemmed |
Seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern Baltic Shield |
title_sort |
seismic noise tomography in regions with small velocity contrasts and strong noise directivity: application to the northern baltic shield |
publisher |
HAL CCSD |
publishDate |
2012 |
url |
https://hal.science/hal-00721895 https://hal.science/hal-00721895/document https://hal.science/hal-00721895/file/Complete_Manuscript.pdf |
genre |
Northern Finland Lapland |
genre_facet |
Northern Finland Lapland |
op_source |
https://hal.science/hal-00721895 2012 |
op_relation |
hal-00721895 https://hal.science/hal-00721895 https://hal.science/hal-00721895/document https://hal.science/hal-00721895/file/Complete_Manuscript.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1797589607787790336 |