气候变化领域集成服务门户(CCPortal): Transport and Localization of Elastic Waves in Two-Dimensional Fractured Media: Consequences on Scattering Attenuation

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DOI	10.1029/2020JB021178
	Transport and Localization of Elastic Waves in Two-Dimensional Fractured Media: Consequences on Scattering Attenuation
	Lei Q.; Sornette D.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	We present numerical simulations of elastic wave transport in two-dimensional fractured media. Natural fracture systems, following a power-law length scaling, are modeled by the discrete fracture network approach for geometrically representing fracture distributions and the displacement discontinuity method for mechanically computing fracture-wave interactions. The model is validated against analytical solutions for wave reflection, transmission, and scattering by single fractures, and then applied to solve the wavefield evolution in synthetic fracture networks. We find that the dimensionless angular frequency ῶ = ωZ/κ plays a crucial role in governing wave transport, where ω, Z, and κ are the angular frequency, seismic impedance, and fracture stiffness, respectively. When ῶ is smaller than the critical frequency ῶc (≈5), waves are in the extended mode, either propagating (for small ῶ) or diffusing by multiple scattering (for intermediate ῶ); as ῶ exceeds ῶc, waves become trapped, entering either the Anderson localization regime (kl* ≈ 1) in well-connected fracture systems or the weak localization regime (kl* > 1) in poorly-connected fracture systems, where k is the incident wavenumber and l* is the mean free path length. Consequently, the inverse quality factor Q−1 scales with ῶ obeying a two-branch power-law dependence, showing significant frequency dependence when ῶ < ῶc and almost frequency independence when ῶ > ῶc. Furthermore, when ῶ < ῶc, the wavefield exhibits a weak dependence on fracture network geometry, whereas when ῶ > ῶc, the fracture network connectivity has an important impact on the wavefield such that strong attenuation occurs in well-connected fracture systems. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Anderson localization; connectivity; dimensionless angular frequency; elastic waves; fracture networks; scattering attenuation
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187055
作者单位	Department of Earth Sciences, ETH Zürich, Zürich, Switzerland; Department of Management, Technology and Economics, ETH Zürich, Zürich, Switzerland; Department of Physics, ETH Zürich, Zürich, Switzerland; Institute of Risk Analysis, Prediction and Management, Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China
推荐引用方式 GB/T 7714	Lei Q.,Sornette D.. Transport and Localization of Elastic Waves in Two-Dimensional Fractured Media: Consequences on Scattering Attenuation[J],2021,126(6).
APA	Lei Q.,&Sornette D..(2021).Transport and Localization of Elastic Waves in Two-Dimensional Fractured Media: Consequences on Scattering Attenuation.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Lei Q.,et al."Transport and Localization of Elastic Waves in Two-Dimensional Fractured Media: Consequences on Scattering Attenuation".Journal of Geophysical Research: Solid Earth 126.6(2021).