Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure
SUMMARY The Pacific Coast of Central North America is a geodynamically complex region which has been subject to various geophysical processes operating on different timescales. Glacial isostatic adjustment (GIA), the ongoing deformational response of the solid Earth to past deglaciation, is an impor...
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Oxford University Press (OUP)
2021
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croxfordunivpr:10.1093/gji/ggab053 2024-06-23T07:53:50+00:00 Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure Yousefi, Maryam Milne, Glenn A Latychev, Konstantin Natural Sciences and Engineering Research Council of Canada University of Ottawa 2021 http://dx.doi.org/10.1093/gji/ggab053 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggab053/36204562/ggab053.pdf http://academic.oup.com/gji/article-pdf/226/1/91/37034548/ggab053.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model Geophysical Journal International volume 226, issue 1, page 91-113 ISSN 0956-540X 1365-246X journal-article 2021 croxfordunivpr https://doi.org/10.1093/gji/ggab053 2024-06-11T04:19:31Z SUMMARY The Pacific Coast of Central North America is a geodynamically complex region which has been subject to various geophysical processes operating on different timescales. Glacial isostatic adjustment (GIA), the ongoing deformational response of the solid Earth to past deglaciation, is an important geodynamic process in this region. In this study, we apply earth models with 3-D structure to determine if the inclusion of lateral structure can explain the poor performance of 1-D models in this region. Three different approaches are used to construct 3-D models of the Earth structure. For the first approach, we adopt an optimal 1-D viscosity structure from previous work and add lateral variations based on four global seismic shear wave velocity anomalies and two global lithosphere thickness models. The results based on these models indicate that the addition of lateral structure significantly impacts modelled RSL changes, but the data-model fits are not improved. The global seismic models are limited in spatial resolution and so two other approaches were considered to produce higher resolution models of 3-D structure: inserting a regional seismic model into two of the global seismic models and, explicitly incorporating regional structure of the Cascadia subduction zone and vicinity, that is the subducting slab, the overlying mantle wedge and the plate boundary interface. The results associated with these higher resolution models do not reveal any clear improvement in satisfying the RSL observations, suggesting that our estimates of lateral structure are inaccurate and/or the data-model misfits are primarily due to limitations in the adopted ice-loading history. The different realizations of 3-D Earth structure gives useful insight to uncertainty associated with this aspect of the GIA model. Our results indicate that improving constraints on the deglacial history of the southwest sector of the Cordilleran ice sheet is an important step towards developing more accurate of GIA models for this region. Article in Journal/Newspaper Ice Sheet Oxford University Press Pacific Geophysical Journal International 226 1 91 113 |
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Open Polar |
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Oxford University Press |
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croxfordunivpr |
language |
English |
description |
SUMMARY The Pacific Coast of Central North America is a geodynamically complex region which has been subject to various geophysical processes operating on different timescales. Glacial isostatic adjustment (GIA), the ongoing deformational response of the solid Earth to past deglaciation, is an important geodynamic process in this region. In this study, we apply earth models with 3-D structure to determine if the inclusion of lateral structure can explain the poor performance of 1-D models in this region. Three different approaches are used to construct 3-D models of the Earth structure. For the first approach, we adopt an optimal 1-D viscosity structure from previous work and add lateral variations based on four global seismic shear wave velocity anomalies and two global lithosphere thickness models. The results based on these models indicate that the addition of lateral structure significantly impacts modelled RSL changes, but the data-model fits are not improved. The global seismic models are limited in spatial resolution and so two other approaches were considered to produce higher resolution models of 3-D structure: inserting a regional seismic model into two of the global seismic models and, explicitly incorporating regional structure of the Cascadia subduction zone and vicinity, that is the subducting slab, the overlying mantle wedge and the plate boundary interface. The results associated with these higher resolution models do not reveal any clear improvement in satisfying the RSL observations, suggesting that our estimates of lateral structure are inaccurate and/or the data-model misfits are primarily due to limitations in the adopted ice-loading history. The different realizations of 3-D Earth structure gives useful insight to uncertainty associated with this aspect of the GIA model. Our results indicate that improving constraints on the deglacial history of the southwest sector of the Cordilleran ice sheet is an important step towards developing more accurate of GIA models for this region. |
author2 |
Natural Sciences and Engineering Research Council of Canada University of Ottawa |
format |
Article in Journal/Newspaper |
author |
Yousefi, Maryam Milne, Glenn A Latychev, Konstantin |
spellingShingle |
Yousefi, Maryam Milne, Glenn A Latychev, Konstantin Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure |
author_facet |
Yousefi, Maryam Milne, Glenn A Latychev, Konstantin |
author_sort |
Yousefi, Maryam |
title |
Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure |
title_short |
Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure |
title_full |
Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure |
title_fullStr |
Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure |
title_full_unstemmed |
Glacial isostatic adjustment of the Pacific Coast of North America: the influence of lateral Earth structure |
title_sort |
glacial isostatic adjustment of the pacific coast of north america: the influence of lateral earth structure |
publisher |
Oxford University Press (OUP) |
publishDate |
2021 |
url |
http://dx.doi.org/10.1093/gji/ggab053 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggab053/36204562/ggab053.pdf http://academic.oup.com/gji/article-pdf/226/1/91/37034548/ggab053.pdf |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Geophysical Journal International volume 226, issue 1, page 91-113 ISSN 0956-540X 1365-246X |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/gji/ggab053 |
container_title |
Geophysical Journal International |
container_volume |
226 |
container_issue |
1 |
container_start_page |
91 |
op_container_end_page |
113 |
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1802645684046790656 |