Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone
High-resolution seismic reflection profiles from the offshore segment of the Littoral Fault Zone (LFZ) near Nan’ao Island were analyzed to investigate fault activity and its potential link to the 1918 M7.3 earthquake. The data reveal a ~19 km-wide graben bounded by seaward- and landward-dipping norm...
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MDPI AG
2025-06-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/17/13/2153 |
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| author | Hu Yi Wenhuan Zhan Xiaodong Yang Jian Li Xiaochuan Wu Jie Sun Yantao Yao Jiaxian Huang Zelong Ju |
| author_facet | Hu Yi Wenhuan Zhan Xiaodong Yang Jian Li Xiaochuan Wu Jie Sun Yantao Yao Jiaxian Huang Zelong Ju |
| author_sort | Hu Yi |
| collection | DOAJ |
| description | High-resolution seismic reflection profiles from the offshore segment of the Littoral Fault Zone (LFZ) near Nan’ao Island were analyzed to investigate fault activity and its potential link to the 1918 M7.3 earthquake. The data reveal a ~19 km-wide graben bounded by seaward- and landward-dipping normal faults, with fault-propagation folds and growth faults reaching the seafloor. Forward modeling of the fault-propagation fold indicates three discrete episodes of normal dip-slip displacement (~20 m per phase), separated by prolonged quiescent periods, suggesting episodic fault activity and seismic-scale strain accumulation. Despite the regional NW–SE compressional stress regime, active normal faulting is observed, implying vertical stress as the dominant driving force. A gravitational seismic model driven by upper crustal loading is proposed to explain both the fault motion and the down-draw tsunami observed during the 1918 event. These findings offer new insights into intraplate seismogenic mechanisms and associated hazards along the South China coast. |
| format | Article |
| id | doaj-art-e632ed6299f84645b9d40bb6938dc442 |
| institution | Kabale University |
| issn | 2072-4292 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
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| series | Remote Sensing |
| spelling | doaj-art-e632ed6299f84645b9d40bb6938dc4422025-08-20T03:29:02ZengMDPI AGRemote Sensing2072-42922025-06-011713215310.3390/rs17132153Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault ZoneHu Yi0Wenhuan Zhan1Xiaodong Yang2Jian Li3Xiaochuan Wu4Jie Sun5Yantao Yao6Jiaxian Huang7Zelong Ju8Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaNational Joint Local Engineering Research Center for Shale Gas Exploration and Development, Chongqing Institute of Geology and Mineral Resources, Chongqing 401120, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaKey Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, ChinaHigh-resolution seismic reflection profiles from the offshore segment of the Littoral Fault Zone (LFZ) near Nan’ao Island were analyzed to investigate fault activity and its potential link to the 1918 M7.3 earthquake. The data reveal a ~19 km-wide graben bounded by seaward- and landward-dipping normal faults, with fault-propagation folds and growth faults reaching the seafloor. Forward modeling of the fault-propagation fold indicates three discrete episodes of normal dip-slip displacement (~20 m per phase), separated by prolonged quiescent periods, suggesting episodic fault activity and seismic-scale strain accumulation. Despite the regional NW–SE compressional stress regime, active normal faulting is observed, implying vertical stress as the dominant driving force. A gravitational seismic model driven by upper crustal loading is proposed to explain both the fault motion and the down-draw tsunami observed during the 1918 event. These findings offer new insights into intraplate seismogenic mechanisms and associated hazards along the South China coast.https://www.mdpi.com/2072-4292/17/13/2153Littoral Fault Zone (LFZ)active faultactive foldmonoclineshallow deformationgraben |
| spellingShingle | Hu Yi Wenhuan Zhan Xiaodong Yang Jian Li Xiaochuan Wu Jie Sun Yantao Yao Jiaxian Huang Zelong Ju Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone Remote Sensing Littoral Fault Zone (LFZ) active fault active fold monocline shallow deformation graben |
| title | Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone |
| title_full | Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone |
| title_fullStr | Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone |
| title_full_unstemmed | Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone |
| title_short | Shallow Structural Deformation Reveals Intraplate Seismicity Triggered by Graben Motion in the South China Littoral Fault Zone |
| title_sort | shallow structural deformation reveals intraplate seismicity triggered by graben motion in the south china littoral fault zone |
| topic | Littoral Fault Zone (LFZ) active fault active fold monocline shallow deformation graben |
| url | https://www.mdpi.com/2072-4292/17/13/2153 |
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