Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling
Accurate earthquake source parameters are crucial for understanding plate tectonics, yet, it is difficult to determine these parameters precisely for offshore events, especially for outer-rise earthquakes, as the limited availability of direct P or S wave data sets from land-based seismic networks a...
| Main Authors: | , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2024
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| Online Access: | https://hdl.handle.net/10356/178871 |
| _version_ | 1811683011878453248 |
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| author | Qian, Yunyi Chen, Xiaofei Wu, Wenbo Wei, Shengji Ni, Sidao Xu, Min Qin, Yanfang Nakamura, Yasuyuki Zhou, Yong Sun, Daoyuan |
| author2 | Asian School of the Environment |
| author_facet | Asian School of the Environment Qian, Yunyi Chen, Xiaofei Wu, Wenbo Wei, Shengji Ni, Sidao Xu, Min Qin, Yanfang Nakamura, Yasuyuki Zhou, Yong Sun, Daoyuan |
| author_sort | Qian, Yunyi |
| collection | NTU |
| description | Accurate earthquake source parameters are crucial for understanding plate tectonics, yet, it is difficult to determine these parameters precisely for offshore events, especially for outer-rise earthquakes, as the limited availability of direct P or S wave data sets from land-based seismic networks and the unsuitability of simplified 1D methods for the complex 3D structures of subducting systems. To overcome these challenges, we employ an efficient hybrid numerical simulation method to model these 3D structural effects on teleseismic P/SH and P-coda waves and determine the reliable centroid locations and focal mechanisms of outer-rise normal-faulting earthquakes in northeastern Japan. Two M6+ events with reliable locations from ocean bottom seismic observations are utilized to calibrate the 3D velocity structure. Our findings indicate that 3D synthetic waveforms are sensitive to both event location, thanks to bathymetry and water reverberation effects, and the shallow portion of the lithospheric structure. With our preferred velocity model, which has Versus ∼16% lower than the global average, event locations are determined with uncertainties of <5 km for horizontal position and <1 km for depth. The refined event locations in a good match between one of the nodal strikes and the high-resolution bathymetry, enabling the determination of the causative fault plane. Our results reveal that trench-ward dipping normal faults are more active, with three parallel to the trench as expected, while five are associated with the abyssal hills. The significant velocity reduction in the uppermost lithosphere suggests abundant water migrating through active normal faults, enhancing both mineral alteration and pore density. |
| first_indexed | 2024-10-01T04:05:57Z |
| format | Journal Article |
| id | ntu-10356/178871 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:05:57Z |
| publishDate | 2024 |
| record_format | dspace |
| spelling | ntu-10356/1788712024-07-15T15:30:40Z Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling Qian, Yunyi Chen, Xiaofei Wu, Wenbo Wei, Shengji Ni, Sidao Xu, Min Qin, Yanfang Nakamura, Yasuyuki Zhou, Yong Sun, Daoyuan Asian School of the Environment Earth Observatory of Singapore Earth and Environmental Sciences Earthquake Hydration Accurate earthquake source parameters are crucial for understanding plate tectonics, yet, it is difficult to determine these parameters precisely for offshore events, especially for outer-rise earthquakes, as the limited availability of direct P or S wave data sets from land-based seismic networks and the unsuitability of simplified 1D methods for the complex 3D structures of subducting systems. To overcome these challenges, we employ an efficient hybrid numerical simulation method to model these 3D structural effects on teleseismic P/SH and P-coda waves and determine the reliable centroid locations and focal mechanisms of outer-rise normal-faulting earthquakes in northeastern Japan. Two M6+ events with reliable locations from ocean bottom seismic observations are utilized to calibrate the 3D velocity structure. Our findings indicate that 3D synthetic waveforms are sensitive to both event location, thanks to bathymetry and water reverberation effects, and the shallow portion of the lithospheric structure. With our preferred velocity model, which has Versus ∼16% lower than the global average, event locations are determined with uncertainties of <5 km for horizontal position and <1 km for depth. The refined event locations in a good match between one of the nodal strikes and the high-resolution bathymetry, enabling the determination of the causative fault plane. Our results reveal that trench-ward dipping normal faults are more active, with three parallel to the trench as expected, while five are associated with the abyssal hills. The significant velocity reduction in the uppermost lithosphere suggests abundant water migrating through active normal faults, enhancing both mineral alteration and pore density. Published version Yunyi Qian is supported by the National Natural Science Foundation of China (42274070). Xiaofei Chen is supported by the National Natural Science Foundation of China (U1901602) and Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology (2022B1212010002). Sidao Ni is supported by the National Natural Science Foundation of China (42030311). Min Xu acknowledge s the support from the Guangdong Basic and Applied Basic Research Foundation (2021B1515020023). Yong Zhou is supported by the National Natural Science Foundation of China (42104104). 2024-07-10T00:58:51Z 2024-07-10T00:58:51Z 2024 Journal Article Qian, Y., Chen, X., Wu, W., Wei, S., Ni, S., Xu, M., Qin, Y., Nakamura, Y., Zhou, Y. & Sun, D. (2024). Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern japan, constrained with 3D teleseismic waveform modeling. Journal of Geophysical Research: Solid Earth, 129(6). https://dx.doi.org/10.1029/2024JB028740 2169-9356 https://hdl.handle.net/10356/178871 10.1029/2024JB028740 2-s2.0-85196211043 6 129 en Journal of Geophysical Research: Solid Earth © 2024 American Geophysical Union. All rights reserved. This article may be downloaded for personal use only. Any other use requires prior permission of the copyright holder. The Version of Record is available online at http://doi.org/10.1029/2024JB028740 application/pdf |
| spellingShingle | Earth and Environmental Sciences Earthquake Hydration Qian, Yunyi Chen, Xiaofei Wu, Wenbo Wei, Shengji Ni, Sidao Xu, Min Qin, Yanfang Nakamura, Yasuyuki Zhou, Yong Sun, Daoyuan Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling |
| title | Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling |
| title_full | Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling |
| title_fullStr | Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling |
| title_full_unstemmed | Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling |
| title_short | Patterns of causative faults of normal earthquakes in the fluid‐rich outer rise of northeastern Japan, constrained with 3D teleseismic waveform modeling |
| title_sort | patterns of causative faults of normal earthquakes in the fluid rich outer rise of northeastern japan constrained with 3d teleseismic waveform modeling |
| topic | Earth and Environmental Sciences Earthquake Hydration |
| url | https://hdl.handle.net/10356/178871 |
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