Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake
Abstract The 2011 Tohoku-oki earthquake produced the most well-recorded postseismic deformation of any megathrust earthquake in the world. Over the last decade, researchers have used a dense and widespread geodetic network of more than 1300 Global Navigation Satellite System (GNSS) stations inland,...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-02-01
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| Series: | Progress in Earth and Planetary Science |
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| Online Access: | https://doi.org/10.1186/s40645-023-00539-1 |
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| author | Sambuddha Dhar Jun Muto Yusaku Ohta Takeshi Iinuma |
| author_facet | Sambuddha Dhar Jun Muto Yusaku Ohta Takeshi Iinuma |
| author_sort | Sambuddha Dhar |
| collection | DOAJ |
| description | Abstract The 2011 Tohoku-oki earthquake produced the most well-recorded postseismic deformation of any megathrust earthquake in the world. Over the last decade, researchers have used a dense and widespread geodetic network of more than 1300 Global Navigation Satellite System (GNSS) stations inland, as well as the about 50 stations on the seafloor, to investigate the various deformation sources responsible for the observed crustal deformation. One of the contributing mechanisms to this crustal deformation is the stress relaxation of the viscoelastic mantle beneath the Japanese arc. As evident in experimental rock physics and geophysical observations, ambient mantle conditions and related rheology are expected to be heterogeneous in space. However, the contribution of such rheological heterogeneities to the postseismic deformation is still poorly understood. Here, we piece together several rheological heterogeneities inferred from the decade-long postseismic deformation of the 2011 Tohoku-oki earthquake. We reviewed more than twenty postseismic models to understand how viscoelastic earth can influence the postseismic surface deformation observed after the Tohoku-oki earthquake. Besides, we employed several synthetic models to tease out the contribution of individual rheological heterogeneities such as depth-dependent rheology of mantle wedge, oceanic asthenosphere, and low-viscosity zone beneath the volcanic front. We demonstrate that the vertical postseismic observation is the key to unravel rheological complexity beneath northeastern Japan. The broader vertical deformation pattern reveals the major viscosity contrast between backarc and forearc, and small-scale subsidence detects the presence of low-viscosity bodies related to arc magmatism. In short, this review paper provides a vista of three-dimensional heterogeneous rheology of viscoelastic earth. These rheological heterogeneities may play a crucial role in bridging the gap between our understanding of different phase of subduction zone earthquake cycle. |
| first_indexed | 2024-04-09T22:32:53Z |
| format | Article |
| id | doaj.art-71cc5c836cf04e32b0bff140e41db9c5 |
| institution | Directory Open Access Journal |
| issn | 2197-4284 |
| language | English |
| last_indexed | 2024-04-09T22:32:53Z |
| publishDate | 2023-02-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Progress in Earth and Planetary Science |
| spelling | doaj.art-71cc5c836cf04e32b0bff140e41db9c52023-03-22T12:40:53ZengSpringerOpenProgress in Earth and Planetary Science2197-42842023-02-0110112710.1186/s40645-023-00539-1Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquakeSambuddha Dhar0Jun Muto1Yusaku Ohta2Takeshi Iinuma3Department of Earth Science, Tohoku UniversityDepartment of Earth Science, Tohoku UniversityResearch Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku UniversityJapan Agency for Marine-Earth Science and TechnologyAbstract The 2011 Tohoku-oki earthquake produced the most well-recorded postseismic deformation of any megathrust earthquake in the world. Over the last decade, researchers have used a dense and widespread geodetic network of more than 1300 Global Navigation Satellite System (GNSS) stations inland, as well as the about 50 stations on the seafloor, to investigate the various deformation sources responsible for the observed crustal deformation. One of the contributing mechanisms to this crustal deformation is the stress relaxation of the viscoelastic mantle beneath the Japanese arc. As evident in experimental rock physics and geophysical observations, ambient mantle conditions and related rheology are expected to be heterogeneous in space. However, the contribution of such rheological heterogeneities to the postseismic deformation is still poorly understood. Here, we piece together several rheological heterogeneities inferred from the decade-long postseismic deformation of the 2011 Tohoku-oki earthquake. We reviewed more than twenty postseismic models to understand how viscoelastic earth can influence the postseismic surface deformation observed after the Tohoku-oki earthquake. Besides, we employed several synthetic models to tease out the contribution of individual rheological heterogeneities such as depth-dependent rheology of mantle wedge, oceanic asthenosphere, and low-viscosity zone beneath the volcanic front. We demonstrate that the vertical postseismic observation is the key to unravel rheological complexity beneath northeastern Japan. The broader vertical deformation pattern reveals the major viscosity contrast between backarc and forearc, and small-scale subsidence detects the presence of low-viscosity bodies related to arc magmatism. In short, this review paper provides a vista of three-dimensional heterogeneous rheology of viscoelastic earth. These rheological heterogeneities may play a crucial role in bridging the gap between our understanding of different phase of subduction zone earthquake cycle.https://doi.org/10.1186/s40645-023-00539-1Postseismic deformationGNSS observationsViscoelastic relaxationAfterslipNonlinear rheologyEarthquake deformation cycle |
| spellingShingle | Sambuddha Dhar Jun Muto Yusaku Ohta Takeshi Iinuma Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake Progress in Earth and Planetary Science Postseismic deformation GNSS observations Viscoelastic relaxation Afterslip Nonlinear rheology Earthquake deformation cycle |
| title | Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake |
| title_full | Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake |
| title_fullStr | Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake |
| title_full_unstemmed | Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake |
| title_short | Heterogeneous rheology of Japan subduction zone revealed by postseismic deformation of the 2011 Tohoku-oki earthquake |
| title_sort | heterogeneous rheology of japan subduction zone revealed by postseismic deformation of the 2011 tohoku oki earthquake |
| topic | Postseismic deformation GNSS observations Viscoelastic relaxation Afterslip Nonlinear rheology Earthquake deformation cycle |
| url | https://doi.org/10.1186/s40645-023-00539-1 |
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