Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves

This study presents for the first time an integrated image of the crust and lithospheric mantle of Alaska and its adjacent western shelves of the Chukchi and Bering seas based on joint modeling of potential field data constrained by thermal analysis and seismic data. We also perform 3D forward model...

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Autores: Torné, Montserrat, Jimenez-Munt, Ivone, Vergés Masip, Jaume, Fernández Ortiga, Manel, Carballo, Alberto, Jadamec, Margarete
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::afcb85fff9a2a7910d75087699d89431
Acceso en línea:http://hdl.handle.net/10261/193827
Access Level:acceso abierto
Palabra clave:Artic region
Crustal structure
dynamics: gravity and tectonics
Continental margins: convergent
gravity anomalies and earth structure
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spelling Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelvesTorné, MontserratJimenez-Munt, IvoneVergés Masip, JaumeFernández Ortiga, ManelCarballo, AlbertoJadamec, MargareteArtic regionCrustal structuredynamics: gravity and tectonicsContinental margins: convergentgravity anomalies and earth structureThis study presents for the first time an integrated image of the crust and lithospheric mantle of Alaska and its adjacent western shelves of the Chukchi and Bering seas based on joint modeling of potential field data constrained by thermal analysis and seismic data. We also perform 3D forward modelling and inversion of Bouguer anomalies to analyze density heterogeneities at the crustal level. The obtained crustal model shows northwest-directed long wavelength thickening (32 to 36 km), with additional localized trends of thicker crust in the Brooks Range (40 km) and in the Alaska and St. Elias ranges (50 km). Offshore, 28–30 km thick crust is predicted near the Bearing slope break and 36–38 km in the northern Chukchi Shelf. In interior Alaska, the crustal thickness changes abruptly across the Denali fault, from 34–36 to the north to above 30 km to the south. This sharp crustal thickness gradient agrees with the presence of a crustal tectonic buttress guiding block motion west and south towards the subduction zone. The average crustal density is 2810 kg∙m−3. The denser crust, up to 2910 kg∙m−3, is found south of the Denali Fault likely related to the oceanic nature of the Wrangellia Composite Terrane rocks. Offshore, less dense crust (< 2800 kg∙m−3) is found along the sedimentary basins of the Chukchi and Beaufort shelves. At LAB levels, there is a regional SE–NW trend that coincides with the current Pacific plate motion, with a lithospheric root underneath the Brooks Range, Northern Slope, and Chuckchi Sea, that may correspond to a relic of the Chukotka-Artic Alaska microplate. The obtained lithospheric root (above 180 km) agrees with the presence of a boundary of cold, strong lithosphere that deflects the strain towards the South. South of the Denali Fault the LAB topography is quite complex. East of 150 ° W, below Wrangellia and the eastern side of Chugach terranes, the LAB is much shallower than it is west of this meridian. The NW trending limit separating thinner lithosphere in the east and thicker in the west agrees with the two–tiered slab shape of the subducting Pacific Plate.This research has been funded by the We–Me project (PIE–CSIC–201330E111), AGUR 2017–SGR–847, Alpimed (PIE-CSIC-201530E082), Subtetis (PIE-CSIC-201830E039) and funds from the University of Houston.Peer reviewedOxford University PressUniversity of HoustonJimenez-Munt, Ivone [0000-0003-4178-3585]Torné, Montserrat [0000-0001-6585-4283 ]Fernandez, Manel [0000-0002-4487-2359]Vergés, Jaume [0000-0002-4467-5291]Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]201920192020info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Preprintinfo:eu-repo/semantics/submittedVersionhttp://hdl.handle.net/10261/193827reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttps://doi.org/10.1093/gji/ggz424Síinfo:eu-repo/semantics/openAccessoai:dnet:digitalcsic_::afcb85fff9a2a7910d75087699d894312026-05-22T06:33:51Z
dc.title.none.fl_str_mv Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
title Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
spellingShingle Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
Torné, Montserrat
Artic region
Crustal structure
dynamics: gravity and tectonics
Continental margins: convergent
gravity anomalies and earth structure
title_short Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
title_full Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
title_fullStr Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
title_full_unstemmed Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
title_sort Regional crustal and lithospheric thickness model for alaska, the chukchi shelf, and the inner and outer bering shelves
dc.creator.none.fl_str_mv Torné, Montserrat
Jimenez-Munt, Ivone
Vergés Masip, Jaume
Fernández Ortiga, Manel
Carballo, Alberto
Jadamec, Margarete
author Torné, Montserrat
author_facet Torné, Montserrat
Jimenez-Munt, Ivone
Vergés Masip, Jaume
Fernández Ortiga, Manel
Carballo, Alberto
Jadamec, Margarete
author_role author
author2 Jimenez-Munt, Ivone
Vergés Masip, Jaume
Fernández Ortiga, Manel
Carballo, Alberto
Jadamec, Margarete
author2_role author
author
author
author
author
dc.contributor.none.fl_str_mv University of Houston
Jimenez-Munt, Ivone [0000-0003-4178-3585]
Torné, Montserrat [0000-0001-6585-4283 ]
Fernandez, Manel [0000-0002-4487-2359]
Vergés, Jaume [0000-0002-4467-5291]
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Artic region
Crustal structure
dynamics: gravity and tectonics
Continental margins: convergent
gravity anomalies and earth structure
topic Artic region
Crustal structure
dynamics: gravity and tectonics
Continental margins: convergent
gravity anomalies and earth structure
description This study presents for the first time an integrated image of the crust and lithospheric mantle of Alaska and its adjacent western shelves of the Chukchi and Bering seas based on joint modeling of potential field data constrained by thermal analysis and seismic data. We also perform 3D forward modelling and inversion of Bouguer anomalies to analyze density heterogeneities at the crustal level. The obtained crustal model shows northwest-directed long wavelength thickening (32 to 36 km), with additional localized trends of thicker crust in the Brooks Range (40 km) and in the Alaska and St. Elias ranges (50 km). Offshore, 28–30 km thick crust is predicted near the Bearing slope break and 36–38 km in the northern Chukchi Shelf. In interior Alaska, the crustal thickness changes abruptly across the Denali fault, from 34–36 to the north to above 30 km to the south. This sharp crustal thickness gradient agrees with the presence of a crustal tectonic buttress guiding block motion west and south towards the subduction zone. The average crustal density is 2810 kg∙m−3. The denser crust, up to 2910 kg∙m−3, is found south of the Denali Fault likely related to the oceanic nature of the Wrangellia Composite Terrane rocks. Offshore, less dense crust (< 2800 kg∙m−3) is found along the sedimentary basins of the Chukchi and Beaufort shelves. At LAB levels, there is a regional SE–NW trend that coincides with the current Pacific plate motion, with a lithospheric root underneath the Brooks Range, Northern Slope, and Chuckchi Sea, that may correspond to a relic of the Chukotka-Artic Alaska microplate. The obtained lithospheric root (above 180 km) agrees with the presence of a boundary of cold, strong lithosphere that deflects the strain towards the South. South of the Denali Fault the LAB topography is quite complex. East of 150 ° W, below Wrangellia and the eastern side of Chugach terranes, the LAB is much shallower than it is west of this meridian. The NW trending limit separating thinner lithosphere in the east and thicker in the west agrees with the two–tiered slab shape of the subducting Pacific Plate.
publishDate 2019
dc.date.none.fl_str_mv 2019
2019
2020
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Preprint
info:eu-repo/semantics/submittedVersion
format article
status_str submittedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/193827
url http://hdl.handle.net/10261/193827
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv https://doi.org/10.1093/gji/ggz424
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Oxford University Press
publisher.none.fl_str_mv Oxford University Press
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812429

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