Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography
More than 20000 arrival-times of teleseismic P- and S-waves were measured over a period of more than 10 years in five separate temporary and two permanent seismic networks covering the Scandinavian (Scandes) Mountains and adjacent areas of the Baltic Shield. The relative traveltime residuals were in...
Published in: | Geophysical Journal International |
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2017
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Online Access: | https://pure.au.dk/portal/da/publications/uppermantle-velocities-below-the-scandinavian-mountains-from-p-and-s-wave-traveltime-tomography(f0a36190-4194-41ba-af72-3a2c7225c74f).html https://doi.org/10.1093/gji/ggw370 https://pure.au.dk/ws/files/132722816/Upper_mantle_velocities_below_the_Scandinavian_Mountains_from_P_and.pdf |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/f0a36190-4194-41ba-af72-3a2c7225c74f 2023-05-15T17:08:19+02:00 Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography Hejrani, Babak Balling, N. Jacobsen, B. H. England, Richard 2017-01 application/pdf https://pure.au.dk/portal/da/publications/uppermantle-velocities-below-the-scandinavian-mountains-from-p-and-s-wave-traveltime-tomography(f0a36190-4194-41ba-af72-3a2c7225c74f).html https://doi.org/10.1093/gji/ggw370 https://pure.au.dk/ws/files/132722816/Upper_mantle_velocities_below_the_Scandinavian_Mountains_from_P_and.pdf eng eng info:eu-repo/semantics/openAccess Hejrani , B , Balling , N , Jacobsen , B H & England , R 2017 , ' Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography ' , Geophysical Journal International , vol. 208 , no. 1 , pp. 177-192 . https://doi.org/10.1093/gji/ggw370 article 2017 ftuniaarhuspubl https://doi.org/10.1093/gji/ggw370 2022-12-21T23:54:25Z More than 20000 arrival-times of teleseismic P- and S-waves were measured over a period of more than 10 years in five separate temporary and two permanent seismic networks covering the Scandinavian (Scandes) Mountains and adjacent areas of the Baltic Shield. The relative traveltime residuals were inverted to 3D tomograms of P- and S- velocities and the VP/VS ratio. Resolution analysis documents that good 3D resolution is available under the dense network south of 64° latitude (Southern Scandes Mountains), and patchier, but highly useful resolution is available further north, where station coverage is more uneven. A pronounced upper-mantle velocity boundary (UMVB), transecting the study region is defined. It runs from SE Norway (east of the Oslo Graben) across the mountains to the Norwegian coast near Trondheim (around the Møre-Trøndelag Fault Complex), from where it follows the coast and runs between Lofoten and the crest of the Northern Scandes Mountains and stays off the coast further north. Seismic velocities in the depth interval 100-300 km change across the UMVB from low relative VP and even lower relative VS on the western side to high relative VP and even higher relative VS to the east. Therefore, this main velocity boundary also separates relatively high VP/VS ratio to the west and relatively low VP/VS to the east. Under the Southern Scandes Mountains (most of southern Norway) we find low relative VP, even lower relative VS and hence high VP/VS. These velocity values are indicative of thinner lithosphere, higher temperature and less depletion and/or fluid content, and possible even partial melt in a relatively shallow asthenosphere. At first sight, this might support the idea of a mantle buoyancy source for the high topography. Under the Northern Scandes Mountains we find the opposite condition: High relative VP, even higher relative VS and hence low VP/VS, consistent with thick dry depleted lithosphere, similar to what is found in most of the Baltic Shield. This shows that upper-mantle velocity ... Article in Journal/Newspaper Lofoten Aarhus University: Research Lofoten Norway Geophysical Journal International 208 1 177 192 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
description |
More than 20000 arrival-times of teleseismic P- and S-waves were measured over a period of more than 10 years in five separate temporary and two permanent seismic networks covering the Scandinavian (Scandes) Mountains and adjacent areas of the Baltic Shield. The relative traveltime residuals were inverted to 3D tomograms of P- and S- velocities and the VP/VS ratio. Resolution analysis documents that good 3D resolution is available under the dense network south of 64° latitude (Southern Scandes Mountains), and patchier, but highly useful resolution is available further north, where station coverage is more uneven. A pronounced upper-mantle velocity boundary (UMVB), transecting the study region is defined. It runs from SE Norway (east of the Oslo Graben) across the mountains to the Norwegian coast near Trondheim (around the Møre-Trøndelag Fault Complex), from where it follows the coast and runs between Lofoten and the crest of the Northern Scandes Mountains and stays off the coast further north. Seismic velocities in the depth interval 100-300 km change across the UMVB from low relative VP and even lower relative VS on the western side to high relative VP and even higher relative VS to the east. Therefore, this main velocity boundary also separates relatively high VP/VS ratio to the west and relatively low VP/VS to the east. Under the Southern Scandes Mountains (most of southern Norway) we find low relative VP, even lower relative VS and hence high VP/VS. These velocity values are indicative of thinner lithosphere, higher temperature and less depletion and/or fluid content, and possible even partial melt in a relatively shallow asthenosphere. At first sight, this might support the idea of a mantle buoyancy source for the high topography. Under the Northern Scandes Mountains we find the opposite condition: High relative VP, even higher relative VS and hence low VP/VS, consistent with thick dry depleted lithosphere, similar to what is found in most of the Baltic Shield. This shows that upper-mantle velocity ... |
format |
Article in Journal/Newspaper |
author |
Hejrani, Babak Balling, N. Jacobsen, B. H. England, Richard |
spellingShingle |
Hejrani, Babak Balling, N. Jacobsen, B. H. England, Richard Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography |
author_facet |
Hejrani, Babak Balling, N. Jacobsen, B. H. England, Richard |
author_sort |
Hejrani, Babak |
title |
Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography |
title_short |
Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography |
title_full |
Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography |
title_fullStr |
Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography |
title_full_unstemmed |
Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography |
title_sort |
upper-mantle velocities below the scandinavian mountains from p- and s- wave traveltime tomography |
publishDate |
2017 |
url |
https://pure.au.dk/portal/da/publications/uppermantle-velocities-below-the-scandinavian-mountains-from-p-and-s-wave-traveltime-tomography(f0a36190-4194-41ba-af72-3a2c7225c74f).html https://doi.org/10.1093/gji/ggw370 https://pure.au.dk/ws/files/132722816/Upper_mantle_velocities_below_the_Scandinavian_Mountains_from_P_and.pdf |
geographic |
Lofoten Norway |
geographic_facet |
Lofoten Norway |
genre |
Lofoten |
genre_facet |
Lofoten |
op_source |
Hejrani , B , Balling , N , Jacobsen , B H & England , R 2017 , ' Upper-mantle velocities below the Scandinavian Mountains from P- and S- wave traveltime tomography ' , Geophysical Journal International , vol. 208 , no. 1 , pp. 177-192 . https://doi.org/10.1093/gji/ggw370 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1093/gji/ggw370 |
container_title |
Geophysical Journal International |
container_volume |
208 |
container_issue |
1 |
container_start_page |
177 |
op_container_end_page |
192 |
_version_ |
1766064060155035648 |