Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes
Based on a compilation of published and new seismic refraction and multichannel seismic reflection data along the south central Chile margin (33°–46°S), we study the processes of sediment accretion and subduction and their implications on megathrust seismicity. In terms of the frontal accretionary p...
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AGU (American Geophysical Union)
2010
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Online Access: | https://oceanrep.geomar.de/id/eprint/10649/ https://oceanrep.geomar.de/id/eprint/10649/1/Tectonics.pdf https://doi.org/10.1029/2010TC002734 |
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ftoceanrep:oai:oceanrep.geomar.de:10649 2023-05-15T14:13:55+02:00 Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes Contreras-Reyes, Eduardo Flueh, Ernst R. Grevemeyer, Ingo 2010 text https://oceanrep.geomar.de/id/eprint/10649/ https://oceanrep.geomar.de/id/eprint/10649/1/Tectonics.pdf https://doi.org/10.1029/2010TC002734 en eng AGU (American Geophysical Union) https://oceanrep.geomar.de/id/eprint/10649/1/Tectonics.pdf Contreras-Reyes, E., Flueh, E. R. and Grevemeyer, I. (2010) Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes. Open Access Tectonics, 29 (TC6018). DOI 10.1029/2010TC002734 <https://doi.org/10.1029/2010TC002734>. doi:10.1029/2010TC002734 info:eu-repo/semantics/openAccess Article PeerReviewed 2010 ftoceanrep https://doi.org/10.1029/2010TC002734 2023-04-07T14:58:48Z Based on a compilation of published and new seismic refraction and multichannel seismic reflection data along the south central Chile margin (33°–46°S), we study the processes of sediment accretion and subduction and their implications on megathrust seismicity. In terms of the frontal accretionary prism (FAP) size, the marine south central Chile fore arc can be divided in two main segments: (1) the Maule segment (south of the Juan Fernández Ridge and north of the Mocha block) characterized by a relative large FAP (20–40 km wide) and (2) the Chiloé segment (south of the Mocha block and north of the Nazca-Antarctic-South America plates junction) characterized by a small FAP (≤10 km wide). In addition, the Maule and Chiloé segments correlate with a thin (<1 km thick) and thick (∼1.5 km thick) subduction channel, respectively. The Mocha block lies between ∼37.5° and 40°S and is configured by the Chile trench, Mocha and Valdivia fracture zones. This region separates young (0–25 Ma) oceanic lithosphere in the south from old (30–35 Ma) oceanic lithosphere in the north, and it represents a fundamental tectonic boundary separating two different styles of sediment accretion and subduction, respectively. A process responsible for this segmentation could be related to differences in initial angles of subduction which in turn depend on the amplitude of the down-deflected oceanic lithosphere under trench sediment loading. On the other hand, a small FAP along the Chiloé segment is coincident with the rupture area of the trans-Pacific tsunamigenic 1960 earthquake (Mw = 9.5), while a relatively large FAP along the Maule segment is coincident with the rupture area of the 2010 earthquake (Mw = 8.8). Differences in earthquake and tsunami magnitudes between these events can be explained in terms of the FAP size along the Chiloé and Maule segments that control the location of the updip limit of the seismogenic zone. The rupture area of the 1960 event also correlates with a thick subduction channel (Chiloé segment) that may provide ... Article in Journal/Newspaper Antarc* Antarctic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Chile Trench ENVELOPE(-75.760,-75.760,-53.123,-53.123) Chiloé ENVELOPE(-63.983,-63.983,-65.517,-65.517) Pacific Tectonics 29 6 n/a n/a |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Based on a compilation of published and new seismic refraction and multichannel seismic reflection data along the south central Chile margin (33°–46°S), we study the processes of sediment accretion and subduction and their implications on megathrust seismicity. In terms of the frontal accretionary prism (FAP) size, the marine south central Chile fore arc can be divided in two main segments: (1) the Maule segment (south of the Juan Fernández Ridge and north of the Mocha block) characterized by a relative large FAP (20–40 km wide) and (2) the Chiloé segment (south of the Mocha block and north of the Nazca-Antarctic-South America plates junction) characterized by a small FAP (≤10 km wide). In addition, the Maule and Chiloé segments correlate with a thin (<1 km thick) and thick (∼1.5 km thick) subduction channel, respectively. The Mocha block lies between ∼37.5° and 40°S and is configured by the Chile trench, Mocha and Valdivia fracture zones. This region separates young (0–25 Ma) oceanic lithosphere in the south from old (30–35 Ma) oceanic lithosphere in the north, and it represents a fundamental tectonic boundary separating two different styles of sediment accretion and subduction, respectively. A process responsible for this segmentation could be related to differences in initial angles of subduction which in turn depend on the amplitude of the down-deflected oceanic lithosphere under trench sediment loading. On the other hand, a small FAP along the Chiloé segment is coincident with the rupture area of the trans-Pacific tsunamigenic 1960 earthquake (Mw = 9.5), while a relatively large FAP along the Maule segment is coincident with the rupture area of the 2010 earthquake (Mw = 8.8). Differences in earthquake and tsunami magnitudes between these events can be explained in terms of the FAP size along the Chiloé and Maule segments that control the location of the updip limit of the seismogenic zone. The rupture area of the 1960 event also correlates with a thick subduction channel (Chiloé segment) that may provide ... |
format |
Article in Journal/Newspaper |
author |
Contreras-Reyes, Eduardo Flueh, Ernst R. Grevemeyer, Ingo |
spellingShingle |
Contreras-Reyes, Eduardo Flueh, Ernst R. Grevemeyer, Ingo Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
author_facet |
Contreras-Reyes, Eduardo Flueh, Ernst R. Grevemeyer, Ingo |
author_sort |
Contreras-Reyes, Eduardo |
title |
Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
title_short |
Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
title_full |
Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
title_fullStr |
Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
title_full_unstemmed |
Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
title_sort |
tectonic control on sediment accretion and subduction off south central chile: implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes |
publisher |
AGU (American Geophysical Union) |
publishDate |
2010 |
url |
https://oceanrep.geomar.de/id/eprint/10649/ https://oceanrep.geomar.de/id/eprint/10649/1/Tectonics.pdf https://doi.org/10.1029/2010TC002734 |
long_lat |
ENVELOPE(-75.760,-75.760,-53.123,-53.123) ENVELOPE(-63.983,-63.983,-65.517,-65.517) |
geographic |
Antarctic Chile Trench Chiloé Pacific |
geographic_facet |
Antarctic Chile Trench Chiloé Pacific |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
https://oceanrep.geomar.de/id/eprint/10649/1/Tectonics.pdf Contreras-Reyes, E., Flueh, E. R. and Grevemeyer, I. (2010) Tectonic control on sediment accretion and subduction off south central Chile: Implications for coseismic rupture processes of the 1960 and 2010 megathrust earthquakes. Open Access Tectonics, 29 (TC6018). DOI 10.1029/2010TC002734 <https://doi.org/10.1029/2010TC002734>. doi:10.1029/2010TC002734 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2010TC002734 |
container_title |
Tectonics |
container_volume |
29 |
container_issue |
6 |
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n/a |
_version_ |
1766286442400579584 |