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Power law relations in earthquakes from microscopic to macroscopic scales

Understanding the physics of earthquakes is a crucial step towards improving the prediction accuracy of earthquakes. Scale invariance or fractal features are often reported in earthquakes, such as the size distribution of earthquakes, the spatial distribution of hypocenters, and the frequency of aft...

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Autores principales: Meng, Fanzhen, Wong, Louis Ngai Yuen, Zhou, Hui
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6656799/
https://www.ncbi.nlm.nih.gov/pubmed/31341249
http://dx.doi.org/10.1038/s41598-019-46864-8
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author Meng, Fanzhen
Wong, Louis Ngai Yuen
Zhou, Hui
author_facet Meng, Fanzhen
Wong, Louis Ngai Yuen
Zhou, Hui
author_sort Meng, Fanzhen
collection PubMed
description Understanding the physics of earthquakes is a crucial step towards improving the prediction accuracy of earthquakes. Scale invariance or fractal features are often reported in earthquakes, such as the size distribution of earthquakes, the spatial distribution of hypocenters, and the frequency of aftershocks. Here we assess whether other key parameters and quantities involved in earthquakes also conform to the power law. By analyzing a large amount of data collected from the laboratory experiments and field monitoring of earthquakes, we find that the crack density on the two sides of small scale fracture or large scale fault decreases with increasing distance following the power law, and the crack number-crack length distribution is also scale invariant like natural faults. Besides, the earthquake b-value is found to decrease with increasing stress in a power law in the brittle regime of the Earth’s crust. The friction coefficient for dry fault and gouges or for partially saturated gouges decreases with the increasing effective normal stress in a power law. The stress dependency of b-value and friction coefficient is dictated by different mechanisms. Our findings will advance the understanding of earthquake physics, and will enable us to better model, predict and conduct hazard assessment of earthquakes.
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spelling pubmed-66567992019-07-29 Power law relations in earthquakes from microscopic to macroscopic scales Meng, Fanzhen Wong, Louis Ngai Yuen Zhou, Hui Sci Rep Article Understanding the physics of earthquakes is a crucial step towards improving the prediction accuracy of earthquakes. Scale invariance or fractal features are often reported in earthquakes, such as the size distribution of earthquakes, the spatial distribution of hypocenters, and the frequency of aftershocks. Here we assess whether other key parameters and quantities involved in earthquakes also conform to the power law. By analyzing a large amount of data collected from the laboratory experiments and field monitoring of earthquakes, we find that the crack density on the two sides of small scale fracture or large scale fault decreases with increasing distance following the power law, and the crack number-crack length distribution is also scale invariant like natural faults. Besides, the earthquake b-value is found to decrease with increasing stress in a power law in the brittle regime of the Earth’s crust. The friction coefficient for dry fault and gouges or for partially saturated gouges decreases with the increasing effective normal stress in a power law. The stress dependency of b-value and friction coefficient is dictated by different mechanisms. Our findings will advance the understanding of earthquake physics, and will enable us to better model, predict and conduct hazard assessment of earthquakes. Nature Publishing Group UK 2019-07-24 /pmc/articles/PMC6656799/ /pubmed/31341249 http://dx.doi.org/10.1038/s41598-019-46864-8 Text en © The Author(s) 2019 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 license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license 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 license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Meng, Fanzhen
Wong, Louis Ngai Yuen
Zhou, Hui
Power law relations in earthquakes from microscopic to macroscopic scales
title Power law relations in earthquakes from microscopic to macroscopic scales
title_full Power law relations in earthquakes from microscopic to macroscopic scales
title_fullStr Power law relations in earthquakes from microscopic to macroscopic scales
title_full_unstemmed Power law relations in earthquakes from microscopic to macroscopic scales
title_short Power law relations in earthquakes from microscopic to macroscopic scales
title_sort power law relations in earthquakes from microscopic to macroscopic scales
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6656799/
https://www.ncbi.nlm.nih.gov/pubmed/31341249
http://dx.doi.org/10.1038/s41598-019-46864-8
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