Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes
International audience The intra‐arc Liquiñe‐Ofqui Fault System (LOFS) is an active transpressive fault zone located in the Patagonian Andes of Chile. In 2007, a seismic sequence occurred in the Aysén Fjord region of Chilean Patagonia along the LOFS, with a Mw 6.2 main earthquake that triggered doze...
Published in: | Journal of Geophysical Research: Solid Earth |
---|---|
Main Authors: | , , , , , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2020
|
Subjects: | |
Online Access: | https://hal.science/hal-02947327 https://hal.science/hal-02947327/document https://hal.science/hal-02947327/file/706819.pdf https://doi.org/10.1029/2020JB019946 |
id |
ftunivcotedazur:oai:HAL:hal-02947327v1 |
---|---|
record_format |
openpolar |
spelling |
ftunivcotedazur:oai:HAL:hal-02947327v1 2024-05-19T07:30:41+00:00 Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes Villalobos, Angelo Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic de Pascale, Gregory Agurto‐detzel, Hans Departamento de Geofísica Santiago Universidad de Chile = University of Chile Santiago (UCHILE) Universitat de Barcelona (UB) Géoazur (GEOAZUR 7329) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur Université Côte d'Azur (UniCA)-Université Côte d'Azur (UniCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ) 2020-09 https://hal.science/hal-02947327 https://hal.science/hal-02947327/document https://hal.science/hal-02947327/file/706819.pdf https://doi.org/10.1029/2020JB019946 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/2020JB019946 hal-02947327 https://hal.science/hal-02947327 https://hal.science/hal-02947327/document https://hal.science/hal-02947327/file/706819.pdf doi:10.1029/2020JB019946 http://hal.archives-ouvertes.fr/licences/copyright/ info:eu-repo/semantics/OpenAccess ISSN: 2169-9313 EISSN: 2169-9356 Journal of Geophysical Research : Solid Earth https://hal.science/hal-02947327 Journal of Geophysical Research : Solid Earth, 2020, 125 (9), pp.e2020JB019946. ⟨10.1029/2020JB019946⟩ [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics info:eu-repo/semantics/article Journal articles 2020 ftunivcotedazur https://doi.org/10.1029/2020JB019946 2024-05-02T00:46:51Z International audience The intra‐arc Liquiñe‐Ofqui Fault System (LOFS) is an active transpressive fault zone located in the Patagonian Andes of Chile. In 2007, a seismic sequence occurred in the Aysén Fjord region of Chilean Patagonia along the LOFS, with a Mw 6.2 main earthquake that triggered dozens of landslides, some of which induced tsunami waves that caused severe damage and casualties. Through the analysis of high‐resolution seismic reflection and bathymetric data, we identify six submarine faults cutting the Late Quaternary postglacial sedimentary infill of the fjord. The most conspicuous are the dextral‐normal NE‐SW striking Quitralco fault (QF) and the N‐S striking strike‐slip Río Cuervo (RCF) and Punta Cola faults (PCF). Our paleoseismological analysis reveals at least seven paleolandslide events buried in the fjord sediments that were triggered by local paleoearthquakes, which occurred since local ice sheet retreat, that is, circa 12 kyr. By combining tectonic observations with local seismicity data, we propose a seismotectonic model for the evolution of the 2007 seismic sequence where three structures were progressively activated from the depth toward the upper continental crust, causing surface rupture along the PCF and with earthquakes, suggesting only partial ruptures along other faults. Because the other faults did not rupture to the seafloor they remain important sources of seismic hazard. Thus, the last seismic sequence was a consequence of a stress transfer from the lower‐ductile toward the upper‐brittle continental crust, close to the triple junction of the Nazca, South American, and Antarctica Plates. Our results emphasize on the potential synergies between multiple geological and geophysical methods to assess complex events. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet HAL Université Côte d'Azur Journal of Geophysical Research: Solid Earth 125 9 |
institution |
Open Polar |
collection |
HAL Université Côte d'Azur |
op_collection_id |
ftunivcotedazur |
language |
English |
topic |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
spellingShingle |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics Villalobos, Angelo Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic de Pascale, Gregory Agurto‐detzel, Hans Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes |
topic_facet |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
description |
International audience The intra‐arc Liquiñe‐Ofqui Fault System (LOFS) is an active transpressive fault zone located in the Patagonian Andes of Chile. In 2007, a seismic sequence occurred in the Aysén Fjord region of Chilean Patagonia along the LOFS, with a Mw 6.2 main earthquake that triggered dozens of landslides, some of which induced tsunami waves that caused severe damage and casualties. Through the analysis of high‐resolution seismic reflection and bathymetric data, we identify six submarine faults cutting the Late Quaternary postglacial sedimentary infill of the fjord. The most conspicuous are the dextral‐normal NE‐SW striking Quitralco fault (QF) and the N‐S striking strike‐slip Río Cuervo (RCF) and Punta Cola faults (PCF). Our paleoseismological analysis reveals at least seven paleolandslide events buried in the fjord sediments that were triggered by local paleoearthquakes, which occurred since local ice sheet retreat, that is, circa 12 kyr. By combining tectonic observations with local seismicity data, we propose a seismotectonic model for the evolution of the 2007 seismic sequence where three structures were progressively activated from the depth toward the upper continental crust, causing surface rupture along the PCF and with earthquakes, suggesting only partial ruptures along other faults. Because the other faults did not rupture to the seafloor they remain important sources of seismic hazard. Thus, the last seismic sequence was a consequence of a stress transfer from the lower‐ductile toward the upper‐brittle continental crust, close to the triple junction of the Nazca, South American, and Antarctica Plates. Our results emphasize on the potential synergies between multiple geological and geophysical methods to assess complex events. |
author2 |
Departamento de Geofísica Santiago Universidad de Chile = University of Chile Santiago (UCHILE) Universitat de Barcelona (UB) Géoazur (GEOAZUR 7329) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur Université Côte d'Azur (UniCA)-Université Côte d'Azur (UniCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ) |
format |
Article in Journal/Newspaper |
author |
Villalobos, Angelo Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic de Pascale, Gregory Agurto‐detzel, Hans |
author_facet |
Villalobos, Angelo Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic de Pascale, Gregory Agurto‐detzel, Hans |
author_sort |
Villalobos, Angelo |
title |
Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes |
title_short |
Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes |
title_full |
Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes |
title_fullStr |
Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes |
title_full_unstemmed |
Active Faulting, Submarine Surface Rupture, and Seismic Migration Along the Liquiñe‐Ofqui Fault System, Patagonian Andes |
title_sort |
active faulting, submarine surface rupture, and seismic migration along the liquiñe‐ofqui fault system, patagonian andes |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal.science/hal-02947327 https://hal.science/hal-02947327/document https://hal.science/hal-02947327/file/706819.pdf https://doi.org/10.1029/2020JB019946 |
genre |
Antarc* Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctica Ice Sheet |
op_source |
ISSN: 2169-9313 EISSN: 2169-9356 Journal of Geophysical Research : Solid Earth https://hal.science/hal-02947327 Journal of Geophysical Research : Solid Earth, 2020, 125 (9), pp.e2020JB019946. ⟨10.1029/2020JB019946⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2020JB019946 hal-02947327 https://hal.science/hal-02947327 https://hal.science/hal-02947327/document https://hal.science/hal-02947327/file/706819.pdf doi:10.1029/2020JB019946 |
op_rights |
http://hal.archives-ouvertes.fr/licences/copyright/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2020JB019946 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
125 |
container_issue |
9 |
_version_ |
1799488564280426496 |