Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake
Abstract The subducted old and cold Pacific Plate beneath the young Philippine Sea Plate at the Izu‐Bonin trench over the Cenozoic hosts regional deep earthquakes. We investigate slab morphology and stress regimes under different trench motion histories with mantle convection models. Viscosity, temp...
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| Format: | Article |
| Language: | English |
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Wiley
2017-07-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1002/2017GL073989 |
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| author | Ting Yang Michael Gurnis Zhongwen Zhan |
| author_facet | Ting Yang Michael Gurnis Zhongwen Zhan |
| author_sort | Ting Yang |
| collection | DOAJ |
| description | Abstract The subducted old and cold Pacific Plate beneath the young Philippine Sea Plate at the Izu‐Bonin trench over the Cenozoic hosts regional deep earthquakes. We investigate slab morphology and stress regimes under different trench motion histories with mantle convection models. Viscosity, temperature, and deviatoric stress are inherently heterogeneous within the slab, which we link to the occurrence of isolated earthquakes. Models expand on previous suggestions that observed slab morphology variations along the Izu‐Bonin subduction zone, exhibited as shallow slab dip angles in the north and steeper dip angles in the south, are mainly due to variations in the rate of trench retreat from the north (where it is fast) to the south (where it is slow). Geodynamic models consistent with the regional plate tectonics, including oceanic plate age, plate convergence rate, and trench motion history, reproduce the seismologically observed principal stress direction and slab morphology. We suggest that the isolated ~680 km deep, 30 May 2015 Mw 7.9 Bonin Islands earthquake, which lies east of the well‐defined Benioff zone and has its principal compressional stress direction oriented toward the tip of the previously defined Benioff zone, can be explained by Pacific slab buckling in response to the slow trench retreat. |
| format | Article |
| id | doaj-art-08bdd53a16e240d2aa0b81bb4b965d43 |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2017-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-08bdd53a16e240d2aa0b81bb4b965d432025-08-20T01:51:46ZengWileyGeophysical Research Letters0094-82761944-80072017-07-0144136641665010.1002/2017GL073989Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquakeTing Yang0Michael Gurnis1Zhongwen Zhan2Seismological Laboratory California Institute of Technology Pasadena California USASeismological Laboratory California Institute of Technology Pasadena California USASeismological Laboratory California Institute of Technology Pasadena California USAAbstract The subducted old and cold Pacific Plate beneath the young Philippine Sea Plate at the Izu‐Bonin trench over the Cenozoic hosts regional deep earthquakes. We investigate slab morphology and stress regimes under different trench motion histories with mantle convection models. Viscosity, temperature, and deviatoric stress are inherently heterogeneous within the slab, which we link to the occurrence of isolated earthquakes. Models expand on previous suggestions that observed slab morphology variations along the Izu‐Bonin subduction zone, exhibited as shallow slab dip angles in the north and steeper dip angles in the south, are mainly due to variations in the rate of trench retreat from the north (where it is fast) to the south (where it is slow). Geodynamic models consistent with the regional plate tectonics, including oceanic plate age, plate convergence rate, and trench motion history, reproduce the seismologically observed principal stress direction and slab morphology. We suggest that the isolated ~680 km deep, 30 May 2015 Mw 7.9 Bonin Islands earthquake, which lies east of the well‐defined Benioff zone and has its principal compressional stress direction oriented toward the tip of the previously defined Benioff zone, can be explained by Pacific slab buckling in response to the slow trench retreat.https://doi.org/10.1002/2017GL073989trench motionslab dynamicsdeep earthquakeisolated eventsnonlinear viscosityBonin Islands |
| spellingShingle | Ting Yang Michael Gurnis Zhongwen Zhan Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake Geophysical Research Letters trench motion slab dynamics deep earthquake isolated events nonlinear viscosity Bonin Islands |
| title | Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake |
| title_full | Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake |
| title_fullStr | Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake |
| title_full_unstemmed | Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake |
| title_short | Trench motion‐controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake |
| title_sort | trench motion controlled slab morphology and stress variations implications for the isolated 2015 bonin islands deep earthquake |
| topic | trench motion slab dynamics deep earthquake isolated events nonlinear viscosity Bonin Islands |
| url | https://doi.org/10.1002/2017GL073989 |
| work_keys_str_mv | AT tingyang trenchmotioncontrolledslabmorphologyandstressvariationsimplicationsfortheisolated2015boninislandsdeepearthquake AT michaelgurnis trenchmotioncontrolledslabmorphologyandstressvariationsimplicationsfortheisolated2015boninislandsdeepearthquake AT zhongwenzhan trenchmotioncontrolledslabmorphologyandstressvariationsimplicationsfortheisolated2015boninislandsdeepearthquake |