Photos of a rock outcrop and maps of the fault surface.
Corona Heights fault, California. (a) Whole outcrop view. The inset corresponds to the surface shown on (c). (b) Zoom on the fault showing different segments constituting the surface. (c, d) Map of fault surfaces scanned using LiDAR. The inset in (c) corresponds to the patch shown on (d). Credit: Candela et al. [2011], Figure 2(a-d)
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Solid Earth

Earthquakes release energy and result in source properties defined across a wide range of scales that are not represented in conventional frictional laws. Norisugi and Noda [2026] introduce a new rate- and roughness-dependent friction (RRF) law which incorporates both effects from fault slip rate and multi-scale variation in fault topography. By limiting the number of state variables in the RRF formulation, the authors show with efficient earthquake cycle simulation that this multi-scale approach can reproduce a key observed relationship between fracture energy and fault slip.

Although further refinement is needed to better represent roughness evolution, this study marks a major advance in earthquake modeling by demonstrating the necessity and feasibility of incorporating multi-scale fault topography in the characterization of earthquake source process.  

Citation: Norisugi, R., & Noda, H. (2026). Multi-scale rate- and roughness-dependent frictional constitutive law and dynamic earthquake sequence simulation. Journal of Geophysical Research: Solid Earth, 131, e2025JB033580. https://doi.org/10.1029/2025JB033580

—Yajing Liu, Associate Editor, JGR: Solid Earth

Text © 2026. The authors. CC BY-NC-ND 3.0
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