Evolution of the real area of contact during laboratory earthquakes

• 成果类型: Article
• 署名作者: Wu, Baoning; Barbot, Sylvain
• 署名单位: University of Southern California; University of California System; University of California San Diego; Scripps Institution of Oceanography
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10344
• DOI: 10.1073/pnas.2410496122
• 发表日期: 2025-06-10
• 关键词: state-dependent friction; stick-slip; rock friction; normal stress; fault gouge; onset; displacement; STABILITY; mechanics; DYNAMICS

摘要

Empirical slip-rate-and state-dependent friction laws and linear fracture mechanics constitute popular approaches to explaining earthquakes. However, the physics underlying friction laws remain elusive and fracture mechanics does not specify fault strength at the various conditions relevant to crustal faulting. Here, we introduce a physical constitutive framework that augments the traditional approaches by incorporating the real area of contact as the state variable. The physical model explains the dynamics of slow and fast ruptures on transparent materials, as well as the amount of light transmitted across the interface during laboratory ruptures. The constitutive framework elucidates the origin of empirical friction laws, and the simulated ruptures can be described by linear elastic fracture mechanics. Continuous measurements of the physical state variable or its proxies during seismic cycles emerge as a novel tool for probing natural faults and advancing our understanding of the earthquake phenomenon.