Universal Quake Statistics: From Compressed Nanocrystals to Earthquakes

Area of Science:

• Materials Science
• Geophysics
• Statistical Physics

Background:

• Many natural and engineered systems, including crystals, metallic glasses, rocks, and granular materials, deform through intermittent slips or

Purpose of the Study:

• To investigate the universal scaling behavior of slip size distributions across a wide range of materials and length scales.
• To determine if this behavior aligns with self-organized criticality (SOC) or a stress-tuned critical state.
• To develop a model explaining the observed phenomena and enabling cross-scale predictions.

Main Methods:

• Comparative analysis of slip size distributions and statistical properties across systems spanning 12 orders of magnitude in length scale.
• Mathematical modeling using a mean-field approach for avalanches of slipping weak spots.

Main Results:

• Identified identical scaling behavior, specifically a power law with an exponential cutoff, in slip size distributions across diverse materials.
• Observed that the cutoff size is tunable with applied stress, indicating a "tuned critical" state, not SOC.
• A mean-field model successfully predicted the observed distributions and stress-dependent cutoff.

Conclusions:

• Deformation in systems from nanocrystals to earthquakes shares fundamental statistical properties.
• The observed phenomena are best described by a stress-tuned critical behavior.
• The findings allow for predictions of material behavior across different scales and applied forces.