VENEGAS ARAVENA, PATRICIO ALEJANDRO, Herrera, M. T.
No
Tectonophysics
Article
Científica
2
1
16/07/2026
1,78478E+12
2-s2.0-105039947548
The breakdown zone size, A, defines the critical spatial scale trailing the crack tip where cohesive forces degrade and energy is dissipated. Contrary to previous suggestions that the distribution of these forces is independent of A, this study demonstrates that such independence is invalid under heterogeneous frictional conditions. By incorporating a heterogeneous slip-weakening law into theoretical models and validating the results via the Spectral Element Method (SEM), we establish that the effective breakdown zone size Aeff is directly proportional to the summation of the local critical slip-weakening distances DC. This linear scaling remains robust across both self-arrested and runaway rupture regimes, indicating that the spatial extent of the cohesive zone is intrinsically governed by the fractal distribution of frictional properties. Furthermore, we derive a novel governing constitutive equation within the breakdown zone that couples the shear stress gradient partial derivative tau/partial derivative xi, the slip rate u(center dot), and the spatial variations of DC. Unlike existing models that focus on localized changes in rupture parameters to explain arrest, our work utilizes a fully heterogeneous fractal DC distribution to show that the rupture's arrest is a consequence of the depletion of available elastic energy as the system attempts to sustain an expanding Aeff. Additionally, we show that the slip rate is inversely proportional to the DC gradient; thus, transitions into zones of small DC values trigger bursts of seismic moment and dominate the high-frequency radiation of the source. These findings provide a fundamental mechanical link between fault roughness, energy partitioning, and the complex radiation patterns observed in natural earthquakes.
Heterogeneous friction parameters; Breakdown zone size; Slip-weakening friction law; Spectral element method