A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska
Our understanding of the present-day state and evolution of the Canadian and Alaskan mantle is hindered by a lack of absolute P-wavespeed constraints that provide complementary sensitivity to composition in conjunction with existing S-wavespeed models. Consequently, cratonic modification, orogenic h...
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American Geophysical Union
2023
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Online Access: | http://hdl.handle.net/10044/1/103475 https://doi.org/10.1029/2022JB025745 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/103475 2023-06-11T04:13:54+02:00 A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska Boyce, A Liddell, M Pugh, S Brown, J McMurchie, E Parsons, P Clement, E Burdick, S Darbyshire, F Cottaar, S Bastow, I Schaeffer, A Audet, P Schutt, D Aster, R The Leverhulme Trust 2023-02-23 http://hdl.handle.net/10044/1/103475 https://doi.org/10.1029/2022JB025745 unknown American Geophysical Union Journal of Geophysical Research: Solid Earth 2169-9313 http://hdl.handle.net/10044/1/103475 doi:10.1029/2022JB025745 RPG-2013-332 © 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/ 34 1 0402 Geochemistry 0403 Geology 0404 Geophysics Journal Article 2023 ftimperialcol https://doi.org/10.1029/2022JB025745 2023-04-27T22:43:12Z Our understanding of the present-day state and evolution of the Canadian and Alaskan mantle is hindered by a lack of absolute P-wavespeed constraints that provide complementary sensitivity to composition in conjunction with existing S-wavespeed models. Consequently, cratonic modification, orogenic history of western North America and complexities within the Alaskan Proto-Pacific subduction system remain enigmatic. One challenge concerns the difficulties in extracting absolute arrival-time measurements from often-noisy data recorded by temporary seismograph networks required to fill gaps in continental and global databases. Using the Absolute Arrival-time Recovery Method (AARM), we extract >180,000 new absolute arrival-time residuals from seismograph stations across Canada and Alaska and combine these data with USArray and global arrival-time data from the contiguous US and Alaska. We develop a new absolute P-wavespeed tomographic model, CAP22, spanning North America that significantly improves resolution in Canada and Alaska over previous models. Slow wavespeeds below the Canadian Cordillera sharply abut fast wavespeeds of the continental interior at the Rocky Mountain Trench in southwest Canada. Slow wavespeeds below the Mackenzie Mountains continue farther inland in northwest Canada, indicating Proterozoic-Archean metasomatism of the Slave craton. Inherited tectonic lineaments colocated with this north-south wavespeed boundary suggest that both the crust and mantle may control Cordilleran orogenic processes. In Alaska, fast upper mantle wavespeeds below the Wrangell Volcanic Field favor a conventional subduction related mechanism for volcanism. Finally, seismic evidence for the subducted Kula and Yukon slabs indicate tectonic reconstructions of western North America may require revision. Article in Journal/Newspaper Mackenzie mountains Alaska Yukon Imperial College London: Spiral Canada Pacific Yukon Journal of Geophysical Research: Solid Earth 128 3 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
unknown |
topic |
0402 Geochemistry 0403 Geology 0404 Geophysics |
spellingShingle |
0402 Geochemistry 0403 Geology 0404 Geophysics Boyce, A Liddell, M Pugh, S Brown, J McMurchie, E Parsons, P Clement, E Burdick, S Darbyshire, F Cottaar, S Bastow, I Schaeffer, A Audet, P Schutt, D Aster, R A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska |
topic_facet |
0402 Geochemistry 0403 Geology 0404 Geophysics |
description |
Our understanding of the present-day state and evolution of the Canadian and Alaskan mantle is hindered by a lack of absolute P-wavespeed constraints that provide complementary sensitivity to composition in conjunction with existing S-wavespeed models. Consequently, cratonic modification, orogenic history of western North America and complexities within the Alaskan Proto-Pacific subduction system remain enigmatic. One challenge concerns the difficulties in extracting absolute arrival-time measurements from often-noisy data recorded by temporary seismograph networks required to fill gaps in continental and global databases. Using the Absolute Arrival-time Recovery Method (AARM), we extract >180,000 new absolute arrival-time residuals from seismograph stations across Canada and Alaska and combine these data with USArray and global arrival-time data from the contiguous US and Alaska. We develop a new absolute P-wavespeed tomographic model, CAP22, spanning North America that significantly improves resolution in Canada and Alaska over previous models. Slow wavespeeds below the Canadian Cordillera sharply abut fast wavespeeds of the continental interior at the Rocky Mountain Trench in southwest Canada. Slow wavespeeds below the Mackenzie Mountains continue farther inland in northwest Canada, indicating Proterozoic-Archean metasomatism of the Slave craton. Inherited tectonic lineaments colocated with this north-south wavespeed boundary suggest that both the crust and mantle may control Cordilleran orogenic processes. In Alaska, fast upper mantle wavespeeds below the Wrangell Volcanic Field favor a conventional subduction related mechanism for volcanism. Finally, seismic evidence for the subducted Kula and Yukon slabs indicate tectonic reconstructions of western North America may require revision. |
author2 |
The Leverhulme Trust |
format |
Article in Journal/Newspaper |
author |
Boyce, A Liddell, M Pugh, S Brown, J McMurchie, E Parsons, P Clement, E Burdick, S Darbyshire, F Cottaar, S Bastow, I Schaeffer, A Audet, P Schutt, D Aster, R |
author_facet |
Boyce, A Liddell, M Pugh, S Brown, J McMurchie, E Parsons, P Clement, E Burdick, S Darbyshire, F Cottaar, S Bastow, I Schaeffer, A Audet, P Schutt, D Aster, R |
author_sort |
Boyce, A |
title |
A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska |
title_short |
A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska |
title_full |
A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska |
title_fullStr |
A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska |
title_full_unstemmed |
A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska |
title_sort |
new p-wave tomographic model (cap22) for north america: implications for the subduction and cratonic metasomatic modification history of western canada and alaska |
publisher |
American Geophysical Union |
publishDate |
2023 |
url |
http://hdl.handle.net/10044/1/103475 https://doi.org/10.1029/2022JB025745 |
geographic |
Canada Pacific Yukon |
geographic_facet |
Canada Pacific Yukon |
genre |
Mackenzie mountains Alaska Yukon |
genre_facet |
Mackenzie mountains Alaska Yukon |
op_source |
34 1 |
op_relation |
Journal of Geophysical Research: Solid Earth 2169-9313 http://hdl.handle.net/10044/1/103475 doi:10.1029/2022JB025745 RPG-2013-332 |
op_rights |
© 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1029/2022JB025745 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
128 |
container_issue |
3 |
_version_ |
1768391328891142144 |