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Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area

As the largest water conservancy and hydropower project in China, the Three Gorges Reservoir is a weak seismic activity area before impoundment, but the frequency of earthquakes increases significantly after impoundment. The spatial density scanning method was used to obtain the characteristics of s...

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Autores principales: Zhang, Lifen, Liao, Wulin, Chen, Zhigao, Li, Jinggang, Yao, Yunsheng, Tong, Guangqin, Zhao, Yannan, Zhou, Ziyan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9250497/
https://www.ncbi.nlm.nih.gov/pubmed/35780164
http://dx.doi.org/10.1038/s41598-022-15362-9
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author Zhang, Lifen
Liao, Wulin
Chen, Zhigao
Li, Jinggang
Yao, Yunsheng
Tong, Guangqin
Zhao, Yannan
Zhou, Ziyan
author_facet Zhang, Lifen
Liao, Wulin
Chen, Zhigao
Li, Jinggang
Yao, Yunsheng
Tong, Guangqin
Zhao, Yannan
Zhou, Ziyan
author_sort Zhang, Lifen
collection PubMed
description As the largest water conservancy and hydropower project in China, the Three Gorges Reservoir is a weak seismic activity area before impoundment, but the frequency of earthquakes increases significantly after impoundment. The spatial density scanning method was used to obtain the characteristics of spatio-temporal earthquake distribution in the reservoir area during loading and unloading processes. The results show that the frequencies of earthquakes during the loading and unloading processes were higher than that during the low-water-level operation period, which is well explained by the acoustic emission test results. The seismic b-value, fractal dimension D, and spatial correlation length SCL can be used together to indicate stress criticality. To analyze the impacts of reservoir water loading and unloading on seismicity in the reservoir area, time-scan analyses were performed on the b-value, D-value, and SCL of earthquakes near the Zigui segment and the Badong segment. Previous studies argued that the time-varying characteristics of b-values do not hold predictive significance for earthquakes in the M4.0–6.2 range. However, our study found that the time-varying characteristics of b-values are of predictive significance for earthquakes around M4.0. These seismic parameters decrease significantly before moderate earthquakes but at different rates in different regions.
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spelling pubmed-92504972022-07-04 Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area Zhang, Lifen Liao, Wulin Chen, Zhigao Li, Jinggang Yao, Yunsheng Tong, Guangqin Zhao, Yannan Zhou, Ziyan Sci Rep Article As the largest water conservancy and hydropower project in China, the Three Gorges Reservoir is a weak seismic activity area before impoundment, but the frequency of earthquakes increases significantly after impoundment. The spatial density scanning method was used to obtain the characteristics of spatio-temporal earthquake distribution in the reservoir area during loading and unloading processes. The results show that the frequencies of earthquakes during the loading and unloading processes were higher than that during the low-water-level operation period, which is well explained by the acoustic emission test results. The seismic b-value, fractal dimension D, and spatial correlation length SCL can be used together to indicate stress criticality. To analyze the impacts of reservoir water loading and unloading on seismicity in the reservoir area, time-scan analyses were performed on the b-value, D-value, and SCL of earthquakes near the Zigui segment and the Badong segment. Previous studies argued that the time-varying characteristics of b-values do not hold predictive significance for earthquakes in the M4.0–6.2 range. However, our study found that the time-varying characteristics of b-values are of predictive significance for earthquakes around M4.0. These seismic parameters decrease significantly before moderate earthquakes but at different rates in different regions. Nature Publishing Group UK 2022-07-02 /pmc/articles/PMC9250497/ /pubmed/35780164 http://dx.doi.org/10.1038/s41598-022-15362-9 Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Zhang, Lifen
Liao, Wulin
Chen, Zhigao
Li, Jinggang
Yao, Yunsheng
Tong, Guangqin
Zhao, Yannan
Zhou, Ziyan
Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area
title Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area
title_full Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area
title_fullStr Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area
title_full_unstemmed Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area
title_short Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area
title_sort variations in seismic parameters for the earthquakes during loading and unloading periods in the three gorges reservoir area
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9250497/
https://www.ncbi.nlm.nih.gov/pubmed/35780164
http://dx.doi.org/10.1038/s41598-022-15362-9
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