Active faulting, submarine surface rupture and seismic migration along the Liquiñe‐Ofqui fault system, Patagonian Andes
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...
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Online Access: | https://doi.org/10.1029/2020JB019946 https://archimer.ifremer.fr/doc/00641/75293/75715.pdf https://archimer.ifremer.fr/doc/00641/75293/75716.docx |
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fttriple:oai:gotriple.eu:10670/1.m029re 2023-05-15T13:42:32+02:00 Active faulting, submarine surface rupture and seismic migration along the Liquiñe‐Ofqui fault system, Patagonian Andes Villalobos, Angelo Vargas Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic De Pascale, Gregory P. Agurto‐detzel, Hans 2020-01-01 https://doi.org/10.1029/2020JB019946 https://archimer.ifremer.fr/doc/00641/75293/75715.pdf https://archimer.ifremer.fr/doc/00641/75293/75716.docx en eng American Geophysical Union (AGU) doi:10.1029/2020JB019946 10670/1.m029re https://archimer.ifremer.fr/doc/00641/75293/75715.pdf https://archimer.ifremer.fr/doc/00641/75293/75716.docx Archimer, archive institutionnelle de l'Ifremer Journal Of Geophysical Research-solid Earth (2169-9313) (American Geophysical Union (AGU)), 2020-09 , Vol. 125 , N. 9 , P. e2020JB019946 (26p.) geo demo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2020 fttriple https://doi.org/10.1029/2020JB019946 2023-01-22T18:33:31Z 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 paleo‐landslide events buried in the fjord sediments, that were triggered by local paleoearthquakes, which occurred since local ice‐sheet retreat, i.e. ca. 12 kyrs. 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 towards the upper continental crust, causing surface rupture along the PCF and with earthquakes (i.e. 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 towards 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. Plain Language Summary When crustal faults rupture, the energy released are the earthquakes we feel at the surface of the Earth. Recent studies along strike‐slip faults, demonstrate that these phenomena are often not only related to a single fault, but instead take place along several faults like was ... Text Antarc* Antarctica Ice Sheet Unknown Patagonia Journal of Geophysical Research: Solid Earth 125 9 |
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English |
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geo demo |
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geo demo Villalobos, Angelo Vargas Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic De Pascale, Gregory P. Agurto‐detzel, Hans Active faulting, submarine surface rupture and seismic migration along the Liquiñe‐Ofqui fault system, Patagonian Andes |
topic_facet |
geo demo |
description |
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 paleo‐landslide events buried in the fjord sediments, that were triggered by local paleoearthquakes, which occurred since local ice‐sheet retreat, i.e. ca. 12 kyrs. 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 towards the upper continental crust, causing surface rupture along the PCF and with earthquakes (i.e. 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 towards 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. Plain Language Summary When crustal faults rupture, the energy released are the earthquakes we feel at the surface of the Earth. Recent studies along strike‐slip faults, demonstrate that these phenomena are often not only related to a single fault, but instead take place along several faults like was ... |
format |
Text |
author |
Villalobos, Angelo Vargas Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic De Pascale, Gregory P. Agurto‐detzel, Hans |
author_facet |
Villalobos, Angelo Vargas Easton, Gabriel Maksymowicz, Andrei Ruiz, Sergio Lastras, Galderic De Pascale, Gregory P. 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 |
American Geophysical Union (AGU) |
publishDate |
2020 |
url |
https://doi.org/10.1029/2020JB019946 https://archimer.ifremer.fr/doc/00641/75293/75715.pdf https://archimer.ifremer.fr/doc/00641/75293/75716.docx |
geographic |
Patagonia |
geographic_facet |
Patagonia |
genre |
Antarc* Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctica Ice Sheet |
op_source |
Archimer, archive institutionnelle de l'Ifremer Journal Of Geophysical Research-solid Earth (2169-9313) (American Geophysical Union (AGU)), 2020-09 , Vol. 125 , N. 9 , P. e2020JB019946 (26p.) |
op_relation |
doi:10.1029/2020JB019946 10670/1.m029re https://archimer.ifremer.fr/doc/00641/75293/75715.pdf https://archimer.ifremer.fr/doc/00641/75293/75716.docx |
op_doi |
https://doi.org/10.1029/2020JB019946 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
125 |
container_issue |
9 |
_version_ |
1766169129396469760 |