P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions
Abstract We present the first 3‐D images of P‐wave radial anisotropy (RAN) and azimuthal anisotropy (AAN) down to 750‐km depth beneath Greenland and surrounding regions. Three P‐wave velocity models (isotropic, RAN, and AAN) are determined by applying a regional tomographic method to simultaneously...
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American Geophysical Union (AGU)
2021
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ftdoajarticles:oai:doaj.org/article:461b6f9154fc498399e44cd601ca49a3 2023-05-15T15:35:02+02:00 P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions Genti Toyokuni Dapeng Zhao 2021-12-01T00:00:00Z https://doi.org/10.1029/2021EA001800 https://doaj.org/article/461b6f9154fc498399e44cd601ca49a3 EN eng American Geophysical Union (AGU) https://doi.org/10.1029/2021EA001800 https://doaj.org/toc/2333-5084 2333-5084 doi:10.1029/2021EA001800 https://doaj.org/article/461b6f9154fc498399e44cd601ca49a3 Earth and Space Science, Vol 8, Iss 12, Pp n/a-n/a (2021) seismic anisotropy Greenland hot mantle plume seismic tomography radial anisotropy (RAN) azimuthal anisotropy (AAN) Astronomy QB1-991 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.1029/2021EA001800 2022-12-31T10:58:15Z Abstract We present the first 3‐D images of P‐wave radial anisotropy (RAN) and azimuthal anisotropy (AAN) down to 750‐km depth beneath Greenland and surrounding regions. Three P‐wave velocity models (isotropic, RAN, and AAN) are determined by applying a regional tomographic method to simultaneously invert P wave arrival times of 1,309 local events and P wave relative traveltime residuals of 7,202 teleseismic events, which were recorded mainly by the latest GLISN network. A high‐velocity body located beneath northeast Greenland (NEG) exhibits a strong negative RAN and a strong AAN with N‐S to NE‐SW oriented fast‐velocity directions (FVDs). The FVDs are generally consistent with the direction of the fold axis of the Caledonian fold belt, which outcrops in NEG. Beneath the Iceland, Jan Mayen, and Svalbard hotspots, a strong positive RAN and a negligible or weak AAN are revealed, which may reflect effects of upwelling mantle plumes. Among the three hotspots, a weak AAN with a constant FVD is only revealed beneath Iceland, which may reflect the existence of background mantle flow. The RAN and AAN features beneath the Labrador Sea, Davis Strait, and Baffin Bay suggest the following scenario on breakup between Greenland and Canada: the breakup was initiated at the Labrador Sea due to local mantle upwelling, but the northward propagation of the breakup was blocked by a strong high‐velocity anomaly beneath Davis Strait; the opening of Baffin Bay might be caused passively by far‐field plate forces. Article in Journal/Newspaper Baffin Bay Baffin Bay Baffin Davis Strait Greenland Iceland Jan Mayen Labrador Sea Svalbard Directory of Open Access Journals: DOAJ Articles Svalbard Baffin Bay Canada Greenland Jan Mayen Svalbard ENVELOPE(20.000,20.000,78.000,78.000) Earth and Space Science 8 12 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
seismic anisotropy Greenland hot mantle plume seismic tomography radial anisotropy (RAN) azimuthal anisotropy (AAN) Astronomy QB1-991 Geology QE1-996.5 |
spellingShingle |
seismic anisotropy Greenland hot mantle plume seismic tomography radial anisotropy (RAN) azimuthal anisotropy (AAN) Astronomy QB1-991 Geology QE1-996.5 Genti Toyokuni Dapeng Zhao P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions |
topic_facet |
seismic anisotropy Greenland hot mantle plume seismic tomography radial anisotropy (RAN) azimuthal anisotropy (AAN) Astronomy QB1-991 Geology QE1-996.5 |
description |
Abstract We present the first 3‐D images of P‐wave radial anisotropy (RAN) and azimuthal anisotropy (AAN) down to 750‐km depth beneath Greenland and surrounding regions. Three P‐wave velocity models (isotropic, RAN, and AAN) are determined by applying a regional tomographic method to simultaneously invert P wave arrival times of 1,309 local events and P wave relative traveltime residuals of 7,202 teleseismic events, which were recorded mainly by the latest GLISN network. A high‐velocity body located beneath northeast Greenland (NEG) exhibits a strong negative RAN and a strong AAN with N‐S to NE‐SW oriented fast‐velocity directions (FVDs). The FVDs are generally consistent with the direction of the fold axis of the Caledonian fold belt, which outcrops in NEG. Beneath the Iceland, Jan Mayen, and Svalbard hotspots, a strong positive RAN and a negligible or weak AAN are revealed, which may reflect effects of upwelling mantle plumes. Among the three hotspots, a weak AAN with a constant FVD is only revealed beneath Iceland, which may reflect the existence of background mantle flow. The RAN and AAN features beneath the Labrador Sea, Davis Strait, and Baffin Bay suggest the following scenario on breakup between Greenland and Canada: the breakup was initiated at the Labrador Sea due to local mantle upwelling, but the northward propagation of the breakup was blocked by a strong high‐velocity anomaly beneath Davis Strait; the opening of Baffin Bay might be caused passively by far‐field plate forces. |
format |
Article in Journal/Newspaper |
author |
Genti Toyokuni Dapeng Zhao |
author_facet |
Genti Toyokuni Dapeng Zhao |
author_sort |
Genti Toyokuni |
title |
P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions |
title_short |
P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions |
title_full |
P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions |
title_fullStr |
P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions |
title_full_unstemmed |
P‐Wave Tomography for 3‐D Radial and Azimuthal Anisotropy Beneath Greenland and Surrounding Regions |
title_sort |
p‐wave tomography for 3‐d radial and azimuthal anisotropy beneath greenland and surrounding regions |
publisher |
American Geophysical Union (AGU) |
publishDate |
2021 |
url |
https://doi.org/10.1029/2021EA001800 https://doaj.org/article/461b6f9154fc498399e44cd601ca49a3 |
long_lat |
ENVELOPE(20.000,20.000,78.000,78.000) |
geographic |
Svalbard Baffin Bay Canada Greenland Jan Mayen Svalbard |
geographic_facet |
Svalbard Baffin Bay Canada Greenland Jan Mayen Svalbard |
genre |
Baffin Bay Baffin Bay Baffin Davis Strait Greenland Iceland Jan Mayen Labrador Sea Svalbard |
genre_facet |
Baffin Bay Baffin Bay Baffin Davis Strait Greenland Iceland Jan Mayen Labrador Sea Svalbard |
op_source |
Earth and Space Science, Vol 8, Iss 12, Pp n/a-n/a (2021) |
op_relation |
https://doi.org/10.1029/2021EA001800 https://doaj.org/toc/2333-5084 2333-5084 doi:10.1029/2021EA001800 https://doaj.org/article/461b6f9154fc498399e44cd601ca49a3 |
op_doi |
https://doi.org/10.1029/2021EA001800 |
container_title |
Earth and Space Science |
container_volume |
8 |
container_issue |
12 |
_version_ |
1766365335777181696 |