Multi‐Layer Seismic Anisotropy Beneath Greenland
Abstract Seismic anisotropy provides insight into past episodes of lithospheric deformation and the orientations of strain in the underlying asthenosphere. The Greenland mantle has played host to a rich history of tectonic processes, including multiple orogenies and plume‐lithosphere interactions. T...
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ftdoajarticles:oai:doaj.org/article:418ea93c089d4836b957e4e5ce8d417b 2023-12-03T10:23:19+01:00 Multi‐Layer Seismic Anisotropy Beneath Greenland Erica M. Nathan Anant Hariharan Darien Florez Karen M. Fischer 2021-05-01T00:00:00Z https://doi.org/10.1029/2020GC009512 https://doaj.org/article/418ea93c089d4836b957e4e5ce8d417b EN eng Wiley https://doi.org/10.1029/2020GC009512 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2020GC009512 https://doaj.org/article/418ea93c089d4836b957e4e5ce8d417b Geochemistry, Geophysics, Geosystems, Vol 22, Iss 5, Pp n/a-n/a (2021) anisotropy craton Greenland mantle dynamics shear‐wave splitting Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.1029/2020GC009512 2023-11-05T01:36:02Z Abstract Seismic anisotropy provides insight into past episodes of lithospheric deformation and the orientations of strain in the underlying asthenosphere. The Greenland mantle has played host to a rich history of tectonic processes, including multiple orogenies and plume‐lithosphere interactions. This study presents new measurements of SKS splitting that reveal strong variations in fast polarization direction with back‐azimuth that are consistent across Greenland, including at stations where splitting measurements have not previously been reported. We compared observed fast polarization directions to the predictions of two‐layer models with olivine‐orthopyroxene anisotropy. The family of models that provides acceptable misfits at 95% confidence indicates an upper layer olivine a‐axis azimuth of 222–236°, a lower layer olivine a‐axis azimuth of 114–130°, and non‐zero a‐axis plunges. These models are consistent with an upper layer of lithospheric anisotropy due to Proterozoic and Archean orogenic fabrics, and a lower layer of anisotropy corresponding to either asthenospheric flow aligned approximately parallel to the direction of absolute plate motion and plunging due to lithospheric topography or dipping lithospheric structures created by episodes of paleo‐convergence. Article in Journal/Newspaper Greenland Directory of Open Access Journals: DOAJ Articles Greenland Geochemistry, Geophysics, Geosystems 22 5 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
anisotropy craton Greenland mantle dynamics shear‐wave splitting Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
anisotropy craton Greenland mantle dynamics shear‐wave splitting Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 Erica M. Nathan Anant Hariharan Darien Florez Karen M. Fischer Multi‐Layer Seismic Anisotropy Beneath Greenland |
topic_facet |
anisotropy craton Greenland mantle dynamics shear‐wave splitting Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract Seismic anisotropy provides insight into past episodes of lithospheric deformation and the orientations of strain in the underlying asthenosphere. The Greenland mantle has played host to a rich history of tectonic processes, including multiple orogenies and plume‐lithosphere interactions. This study presents new measurements of SKS splitting that reveal strong variations in fast polarization direction with back‐azimuth that are consistent across Greenland, including at stations where splitting measurements have not previously been reported. We compared observed fast polarization directions to the predictions of two‐layer models with olivine‐orthopyroxene anisotropy. The family of models that provides acceptable misfits at 95% confidence indicates an upper layer olivine a‐axis azimuth of 222–236°, a lower layer olivine a‐axis azimuth of 114–130°, and non‐zero a‐axis plunges. These models are consistent with an upper layer of lithospheric anisotropy due to Proterozoic and Archean orogenic fabrics, and a lower layer of anisotropy corresponding to either asthenospheric flow aligned approximately parallel to the direction of absolute plate motion and plunging due to lithospheric topography or dipping lithospheric structures created by episodes of paleo‐convergence. |
format |
Article in Journal/Newspaper |
author |
Erica M. Nathan Anant Hariharan Darien Florez Karen M. Fischer |
author_facet |
Erica M. Nathan Anant Hariharan Darien Florez Karen M. Fischer |
author_sort |
Erica M. Nathan |
title |
Multi‐Layer Seismic Anisotropy Beneath Greenland |
title_short |
Multi‐Layer Seismic Anisotropy Beneath Greenland |
title_full |
Multi‐Layer Seismic Anisotropy Beneath Greenland |
title_fullStr |
Multi‐Layer Seismic Anisotropy Beneath Greenland |
title_full_unstemmed |
Multi‐Layer Seismic Anisotropy Beneath Greenland |
title_sort |
multi‐layer seismic anisotropy beneath greenland |
publisher |
Wiley |
publishDate |
2021 |
url |
https://doi.org/10.1029/2020GC009512 https://doaj.org/article/418ea93c089d4836b957e4e5ce8d417b |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 22, Iss 5, Pp n/a-n/a (2021) |
op_relation |
https://doi.org/10.1029/2020GC009512 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2020GC009512 https://doaj.org/article/418ea93c089d4836b957e4e5ce8d417b |
op_doi |
https://doi.org/10.1029/2020GC009512 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
22 |
container_issue |
5 |
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1784271421595189248 |