3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain
Abstract In southern Chile, the Nazca plate is subducting beneath the South American plate. This region was struck by megathrust earthquakes in 1960 and 2010 and is characterized by the existence of a volcanic chain. In this region, we modeled a three-dimensional thermal structure associated with th...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-01-01
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| Series: | Geoscience Letters |
| Online Access: | https://doi.org/10.1186/s40562-023-00318-2 |
| _version_ | 1797349849302040576 |
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| author | Kaya Iwamoto Nobuaki Suenaga Shoichi Yoshioka Francisco Ortega-Culaciati |
| author_facet | Kaya Iwamoto Nobuaki Suenaga Shoichi Yoshioka Francisco Ortega-Culaciati |
| author_sort | Kaya Iwamoto |
| collection | DOAJ |
| description | Abstract In southern Chile, the Nazca plate is subducting beneath the South American plate. This region was struck by megathrust earthquakes in 1960 and 2010 and is characterized by the existence of a volcanic chain. In this region, we modeled a three-dimensional thermal structure associated with the subduction of the Nazca plate by using numerical simulations. Based on the obtained temperature distribution, we determined the updip and downdip limit temperatures for the region ruptured by these two megathrust earthquakes. In addition, the distributions of water content and dehydration gradient were calculated by using appropriate phase diagrams and compared with the location of the volcanic chain. As a result, we infer that the coseismic slip of the 2010 Mw8.8 Maule earthquake occurred only at temperatures lower than and around the 350 °C isotherm that resembles the beginning of the brittle‒ductile transition. We also deduce that the rupture of the 1960 Mw9.5 Valdivia earthquake propagated up to the 450 °C isotherm because the magnitude was considerably large and the young hot plate subducted near the Chile Ridge. In addition, the hydrous minerals in the turbidites, MORB and ultramafic rocks released fluids via dehydration reactions, and dehydrated water migrated upward almost vertically, decreasing the melting point of the mantle wedge and contributing to the formation of the volcanic chain. |
| first_indexed | 2024-03-08T12:37:25Z |
| format | Article |
| id | doaj.art-5633f80bab6a442d9a38a037d558f986 |
| institution | Directory Open Access Journal |
| issn | 2196-4092 |
| language | English |
| last_indexed | 2024-03-08T12:37:25Z |
| publishDate | 2024-01-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Geoscience Letters |
| spelling | doaj.art-5633f80bab6a442d9a38a037d558f9862024-01-21T12:24:03ZengSpringerOpenGeoscience Letters2196-40922024-01-0111111210.1186/s40562-023-00318-23D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chainKaya Iwamoto0Nobuaki Suenaga1Shoichi Yoshioka2Francisco Ortega-Culaciati3Department of Planetology, Graduate School of Science, Kobe UniversityResearch Center for Urban Safety and Security, Kobe UniversityResearch Center for Urban Safety and Security, Kobe UniversityDepartment of Geophysics, Faculty of Physical and Mathematical Sciences, University of ChileAbstract In southern Chile, the Nazca plate is subducting beneath the South American plate. This region was struck by megathrust earthquakes in 1960 and 2010 and is characterized by the existence of a volcanic chain. In this region, we modeled a three-dimensional thermal structure associated with the subduction of the Nazca plate by using numerical simulations. Based on the obtained temperature distribution, we determined the updip and downdip limit temperatures for the region ruptured by these two megathrust earthquakes. In addition, the distributions of water content and dehydration gradient were calculated by using appropriate phase diagrams and compared with the location of the volcanic chain. As a result, we infer that the coseismic slip of the 2010 Mw8.8 Maule earthquake occurred only at temperatures lower than and around the 350 °C isotherm that resembles the beginning of the brittle‒ductile transition. We also deduce that the rupture of the 1960 Mw9.5 Valdivia earthquake propagated up to the 450 °C isotherm because the magnitude was considerably large and the young hot plate subducted near the Chile Ridge. In addition, the hydrous minerals in the turbidites, MORB and ultramafic rocks released fluids via dehydration reactions, and dehydrated water migrated upward almost vertically, decreasing the melting point of the mantle wedge and contributing to the formation of the volcanic chain.https://doi.org/10.1186/s40562-023-00318-2 |
| spellingShingle | Kaya Iwamoto Nobuaki Suenaga Shoichi Yoshioka Francisco Ortega-Culaciati 3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain Geoscience Letters |
| title | 3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain |
| title_full | 3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain |
| title_fullStr | 3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain |
| title_full_unstemmed | 3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain |
| title_short | 3D thermal structural and dehydration modeling in the southern Chile subduction zone and its relationship to interplate earthquakes and the volcanic chain |
| title_sort | 3d thermal structural and dehydration modeling in the southern chile subduction zone and its relationship to interplate earthquakes and the volcanic chain |
| url | https://doi.org/10.1186/s40562-023-00318-2 |
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