Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography.
Regional surface wave tomography in the sub-Antarctic Scotia Sea is helpful in revealing the nature of the crust and the S- wave seismic velocity profile beneath the Bransfield Strait. The joint use of our regional network, global seismographic network stations and local temporary arrays provide bet...
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ftunitriestiris:oai:arts.units.it:11368/1698596 2023-05-15T13:31:04+02:00 Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. VUAN A ROBERTSON MAURICE S. D WIENS D. A PANZA, GIULIANO Vuan, A ROBERTSON MAURICE S., D WIENS D., A Panza, Giuliano 2005 STAMPA http://hdl.handle.net/11368/1698596 eng eng volume:397 firstpage:241 lastpage:259 journal:TECTONOPHYSICS http://hdl.handle.net/11368/1698596 Upper mantle Seismic wave toography info:eu-repo/semantics/article 2005 ftunitriestiris 2023-04-09T06:02:23Z Regional surface wave tomography in the sub-Antarctic Scotia Sea is helpful in revealing the nature of the crust and the S- wave seismic velocity profile beneath the Bransfield Strait. The joint use of our regional network, global seismographic network stations and local temporary arrays provide better lateral resolution than that obtained in our previous studies concerning the Scotia Sea region. Tomographic analysis of data obtained using 10 broad band seismic stations and more than 300 regional events, shows that the Bransfield Basin is characterised by a strong group velocity reduction of 8% with respect to the surrounding areas, in the period range from 15 s to 50 s. The crustal and upper mantle models of the eastern, central and western Bransfield Basin are obtained by joint inversion of Rayleigh and Love local dispersion curves from 15 s to 50 s. In addition our data set is expanded to a broader period interval (1–80 s), in central Bransfield Strait in order to better constrain the upper mantle and shallow crust. The main results can be summarized as follows: (a) the crust thins distinctly from W toward E; the variation is consistent with the type of volcanism, earthquake distribution and bathymetric observations, (b) low upper mantle velocities (soft lid) extend down to depths exceeding 70 km as a consequence of elevated temperatures, (c) the crust beneath the central Bransfield Basin displays continental characteristics with a gradually increasing S-wave velocity distribution versus depth analogous to the East African Rift structure of Kenya, (d) negative velocity gradients are present in the lower crust beneath the eastern Bransfield Basin; these could be interpreted as magmatic bodies originating from decompression melting of the mantle. Article in Journal/Newspaper Antarc* Antarctic Antarctica Bransfield Strait Scotia Sea West Antarctica Università degli studi di Trieste: ArTS (Archivio della ricerca di Trieste) Antarctic West Antarctica Scotia Sea Bransfield Strait |
institution |
Open Polar |
collection |
Università degli studi di Trieste: ArTS (Archivio della ricerca di Trieste) |
op_collection_id |
ftunitriestiris |
language |
English |
topic |
Upper mantle Seismic wave toography |
spellingShingle |
Upper mantle Seismic wave toography VUAN A ROBERTSON MAURICE S. D WIENS D. A PANZA, GIULIANO Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. |
topic_facet |
Upper mantle Seismic wave toography |
description |
Regional surface wave tomography in the sub-Antarctic Scotia Sea is helpful in revealing the nature of the crust and the S- wave seismic velocity profile beneath the Bransfield Strait. The joint use of our regional network, global seismographic network stations and local temporary arrays provide better lateral resolution than that obtained in our previous studies concerning the Scotia Sea region. Tomographic analysis of data obtained using 10 broad band seismic stations and more than 300 regional events, shows that the Bransfield Basin is characterised by a strong group velocity reduction of 8% with respect to the surrounding areas, in the period range from 15 s to 50 s. The crustal and upper mantle models of the eastern, central and western Bransfield Basin are obtained by joint inversion of Rayleigh and Love local dispersion curves from 15 s to 50 s. In addition our data set is expanded to a broader period interval (1–80 s), in central Bransfield Strait in order to better constrain the upper mantle and shallow crust. The main results can be summarized as follows: (a) the crust thins distinctly from W toward E; the variation is consistent with the type of volcanism, earthquake distribution and bathymetric observations, (b) low upper mantle velocities (soft lid) extend down to depths exceeding 70 km as a consequence of elevated temperatures, (c) the crust beneath the central Bransfield Basin displays continental characteristics with a gradually increasing S-wave velocity distribution versus depth analogous to the East African Rift structure of Kenya, (d) negative velocity gradients are present in the lower crust beneath the eastern Bransfield Basin; these could be interpreted as magmatic bodies originating from decompression melting of the mantle. |
author2 |
Vuan, A ROBERTSON MAURICE S., D WIENS D., A Panza, Giuliano |
format |
Article in Journal/Newspaper |
author |
VUAN A ROBERTSON MAURICE S. D WIENS D. A PANZA, GIULIANO |
author_facet |
VUAN A ROBERTSON MAURICE S. D WIENS D. A PANZA, GIULIANO |
author_sort |
VUAN A |
title |
Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. |
title_short |
Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. |
title_full |
Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. |
title_fullStr |
Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. |
title_full_unstemmed |
Crustal and upper mantle S-wave velocity structure beneath the Bransfield Strait (West Antarctica) from regional surface wave tomography. |
title_sort |
crustal and upper mantle s-wave velocity structure beneath the bransfield strait (west antarctica) from regional surface wave tomography. |
publishDate |
2005 |
url |
http://hdl.handle.net/11368/1698596 |
geographic |
Antarctic West Antarctica Scotia Sea Bransfield Strait |
geographic_facet |
Antarctic West Antarctica Scotia Sea Bransfield Strait |
genre |
Antarc* Antarctic Antarctica Bransfield Strait Scotia Sea West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Bransfield Strait Scotia Sea West Antarctica |
op_relation |
volume:397 firstpage:241 lastpage:259 journal:TECTONOPHYSICS http://hdl.handle.net/11368/1698596 |
_version_ |
1766015720936701952 |