Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake
Abstract The 2013 M S 7.0 Lushan earthquake, Sichuan, China, occurred on a blind thrust fault in the southern Longmenshan fault belt. The terrestrial hybrid repeated gravity observation enables us to investigate the redistribution of both surface and deep mass. Here, we find a transient increase in...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-05-01
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| Series: | Communications Earth & Environment |
| Online Access: | https://doi.org/10.1038/s43247-023-00860-z |
| _version_ | 1797811257159450624 |
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| author | Linhai Wang Shi Chen Jiancang Zhuang Bei Zhang Wen Shi Jinling Yang Weimin Xu |
| author_facet | Linhai Wang Shi Chen Jiancang Zhuang Bei Zhang Wen Shi Jinling Yang Weimin Xu |
| author_sort | Linhai Wang |
| collection | DOAJ |
| description | Abstract The 2013 M S 7.0 Lushan earthquake, Sichuan, China, occurred on a blind thrust fault in the southern Longmenshan fault belt. The terrestrial hybrid repeated gravity observation enables us to investigate the redistribution of both surface and deep mass. Here, we find a transient increase in the gravity field about 2 years before the earthquake and a drop after the mainshock. A Bayesian inversion method with spatiotemporal smoothness is employed to extract the apparent density changes. The increase of apparent density on the south of the focal zone is assumed to be related to crustal mass transfer. We introduce a disc-shaped equivalent source model with a homogeneous density to address this hypothesis, and estimate the model parameters by Markov Chain Monte Carlo simulations. As a fluid diffusion footprint is indicated by the seismicity migration in this region, with a fitted diffusion rate of 10 m2 s−1, we conclude that such deep crustal mass transfer may be caused by fluid diffusion. |
| first_indexed | 2024-03-13T07:21:00Z |
| format | Article |
| id | doaj.art-3e27b48567c141f08c319b931e8fc2de |
| institution | Directory Open Access Journal |
| issn | 2662-4435 |
| language | English |
| last_indexed | 2024-03-13T07:21:00Z |
| publishDate | 2023-05-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Earth & Environment |
| spelling | doaj.art-3e27b48567c141f08c319b931e8fc2de2023-06-04T11:39:21ZengNature PortfolioCommunications Earth & Environment2662-44352023-05-014111310.1038/s43247-023-00860-zGravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquakeLinhai Wang0Shi Chen1Jiancang Zhuang2Bei Zhang3Wen Shi4Jinling Yang5Weimin Xu6Institute of Geophysics, China Earthquake AdministrationInstitute of Geophysics, China Earthquake AdministrationThe Institute of Statistical Mathematics, Research Organization of Information and SystemsInstitute of Geophysics, China Earthquake AdministrationInstitute of Geophysics, China Earthquake AdministrationInstitute of Geophysics, China Earthquake AdministrationInstitute of Geophysics, China Earthquake AdministrationAbstract The 2013 M S 7.0 Lushan earthquake, Sichuan, China, occurred on a blind thrust fault in the southern Longmenshan fault belt. The terrestrial hybrid repeated gravity observation enables us to investigate the redistribution of both surface and deep mass. Here, we find a transient increase in the gravity field about 2 years before the earthquake and a drop after the mainshock. A Bayesian inversion method with spatiotemporal smoothness is employed to extract the apparent density changes. The increase of apparent density on the south of the focal zone is assumed to be related to crustal mass transfer. We introduce a disc-shaped equivalent source model with a homogeneous density to address this hypothesis, and estimate the model parameters by Markov Chain Monte Carlo simulations. As a fluid diffusion footprint is indicated by the seismicity migration in this region, with a fitted diffusion rate of 10 m2 s−1, we conclude that such deep crustal mass transfer may be caused by fluid diffusion.https://doi.org/10.1038/s43247-023-00860-z |
| spellingShingle | Linhai Wang Shi Chen Jiancang Zhuang Bei Zhang Wen Shi Jinling Yang Weimin Xu Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake Communications Earth & Environment |
| title | Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake |
| title_full | Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake |
| title_fullStr | Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake |
| title_full_unstemmed | Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake |
| title_short | Gravity field changes reveal deep mass transfer before and after the 2013 Lushan earthquake |
| title_sort | gravity field changes reveal deep mass transfer before and after the 2013 lushan earthquake |
| url | https://doi.org/10.1038/s43247-023-00860-z |
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