Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS
International audience The Yakutat-St. Elias collision in SE Alaska and adjacent Canada represents a prime example of present-day tectonics associated with an indentor corner. Its eastern syntaxis is marked by high exhumation, a sharp structural bend, and strain concentration at the transition from...
Published in: | Journal of Geophysical Research: Solid Earth |
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ftccsdartic:oai:HAL:hal-01243510v1 2023-05-15T18:44:38+02:00 Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS MARECHAL, Anaïs MAZZOTTI, Stephane Elliott, Julie l. Freymueller, Jeffrey T. Schmidt, Michael Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Risques (Géosciences Montpellier) Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Purdue University West Lafayette University of Alaska Fairbanks (UAF) University of Calgary 2015-05 https://hal.archives-ouvertes.fr/hal-01243510 https://hal.archives-ouvertes.fr/hal-01243510/document https://hal.archives-ouvertes.fr/hal-01243510/file/2014JB011842.pdf https://doi.org/10.1002/2014JB011842 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1002/2014JB011842 hal-01243510 https://hal.archives-ouvertes.fr/hal-01243510 https://hal.archives-ouvertes.fr/hal-01243510/document https://hal.archives-ouvertes.fr/hal-01243510/file/2014JB011842.pdf doi:10.1002/2014JB011842 info:eu-repo/semantics/OpenAccess ISSN: 0148-0227 EISSN: 2156-2202 Journal of Geophysical Research https://hal.archives-ouvertes.fr/hal-01243510 Journal of Geophysical Research, American Geophysical Union, 2015, 120 (5), pp.3897-3908. ⟨10.1002/2014JB011842⟩ [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2015 ftccsdartic https://doi.org/10.1002/2014JB011842 2021-10-23T23:43:01Z International audience The Yakutat-St. Elias collision in SE Alaska and adjacent Canada represents a prime example of present-day tectonics associated with an indentor corner. Its eastern syntaxis is marked by high exhumation, a sharp structural bend, and strain concentration at the transition from shortening to oblique transpression. Here we present GPS velocity and strain rate fields that cover the syntaxis, including 11 new stations in the core of the St. Elias Mountains. These data are corrected for transient deformation (glacial isostatic adjustment and postseismic and interseismic loading) to produce residual velocities and strain rates representative of long-term tectonics. The main features of these velocity and strain rate fields are a peak in strain rates (strain knot) in the syntaxis at the junction between the main fault systems and a rapid rotation from convergence-parallel to convergence-normal orientations of the velocities and shortening axes around the syntaxis, leading to shortening across the southern Denali Fault. These features are consistent with the strain and tectonic patterns expected near an indentor corner at the transition from shortening to transpression, with a combination of diffuse and localized deformation. The GPS velocities and strain rates show diffuse deformation around the syntaxis, from pure convergence-parallel shortening in the orogenic wedge to oblique extension that accommodates the strain rotation at the front of the syntaxis. This indentor-corner model also results in a near-zero strike-slip rate on the southern Denali Fault and shows no clear evidence for a throughgoing fault hypothesized to link the Fairweather and Totschunda Faults. Article in Journal/Newspaper Yakutat Alaska Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Canada Fairweather ENVELOPE(-61.083,-61.083,-65.017,-65.017) Journal of Geophysical Research: Solid Earth 120 5 3897 3908 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes MARECHAL, Anaïs MAZZOTTI, Stephane Elliott, Julie l. Freymueller, Jeffrey T. Schmidt, Michael Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS |
topic_facet |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience The Yakutat-St. Elias collision in SE Alaska and adjacent Canada represents a prime example of present-day tectonics associated with an indentor corner. Its eastern syntaxis is marked by high exhumation, a sharp structural bend, and strain concentration at the transition from shortening to oblique transpression. Here we present GPS velocity and strain rate fields that cover the syntaxis, including 11 new stations in the core of the St. Elias Mountains. These data are corrected for transient deformation (glacial isostatic adjustment and postseismic and interseismic loading) to produce residual velocities and strain rates representative of long-term tectonics. The main features of these velocity and strain rate fields are a peak in strain rates (strain knot) in the syntaxis at the junction between the main fault systems and a rapid rotation from convergence-parallel to convergence-normal orientations of the velocities and shortening axes around the syntaxis, leading to shortening across the southern Denali Fault. These features are consistent with the strain and tectonic patterns expected near an indentor corner at the transition from shortening to transpression, with a combination of diffuse and localized deformation. The GPS velocities and strain rates show diffuse deformation around the syntaxis, from pure convergence-parallel shortening in the orogenic wedge to oblique extension that accommodates the strain rotation at the front of the syntaxis. This indentor-corner model also results in a near-zero strike-slip rate on the southern Denali Fault and shows no clear evidence for a throughgoing fault hypothesized to link the Fairweather and Totschunda Faults. |
author2 |
Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Risques (Géosciences Montpellier) Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Purdue University West Lafayette University of Alaska Fairbanks (UAF) University of Calgary |
format |
Article in Journal/Newspaper |
author |
MARECHAL, Anaïs MAZZOTTI, Stephane Elliott, Julie l. Freymueller, Jeffrey T. Schmidt, Michael |
author_facet |
MARECHAL, Anaïs MAZZOTTI, Stephane Elliott, Julie l. Freymueller, Jeffrey T. Schmidt, Michael |
author_sort |
MARECHAL, Anaïs |
title |
Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS |
title_short |
Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS |
title_full |
Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS |
title_fullStr |
Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS |
title_full_unstemmed |
Indentor-corner tectonics in the Yakutat-St. Elias collision constrained by GPS |
title_sort |
indentor-corner tectonics in the yakutat-st. elias collision constrained by gps |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.archives-ouvertes.fr/hal-01243510 https://hal.archives-ouvertes.fr/hal-01243510/document https://hal.archives-ouvertes.fr/hal-01243510/file/2014JB011842.pdf https://doi.org/10.1002/2014JB011842 |
long_lat |
ENVELOPE(-61.083,-61.083,-65.017,-65.017) |
geographic |
Canada Fairweather |
geographic_facet |
Canada Fairweather |
genre |
Yakutat Alaska |
genre_facet |
Yakutat Alaska |
op_source |
ISSN: 0148-0227 EISSN: 2156-2202 Journal of Geophysical Research https://hal.archives-ouvertes.fr/hal-01243510 Journal of Geophysical Research, American Geophysical Union, 2015, 120 (5), pp.3897-3908. ⟨10.1002/2014JB011842⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1002/2014JB011842 hal-01243510 https://hal.archives-ouvertes.fr/hal-01243510 https://hal.archives-ouvertes.fr/hal-01243510/document https://hal.archives-ouvertes.fr/hal-01243510/file/2014JB011842.pdf doi:10.1002/2014JB011842 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1002/2014JB011842 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
120 |
container_issue |
5 |
container_start_page |
3897 |
op_container_end_page |
3908 |
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