The interactions of fault patterns and stress fields during active faulting in Central North China Block: Insights from numerical simulations

Abstract

The interaction of active faults as a factor affecting the mechanisms of large earthquakes has been observed in many places. Most aftershock and clustering earthquake sequences do not recur on the main seismogenic fault but are controlled by fault interactions with adjacent seismic structures. Four groups of conceptual models were generated in this study to determine how the geometry of the seismogenic faults controls the distributions of stress fields and earthquakes. The influences of the fault length ratio, center distance, overlap ratio, echelon distance and fault opening angle were considered in a 2D viscoelastic model. The results indicate that the interaction in the slipping zone is larger when collinear interacting faults are more closely positioned, with one fault lengthening. For noncollinear faults, the interaction is stronger as the inner tips pass each other, which impedes their growth after some degree of overlap. Additionally, fault interaction at the slipping zone becomes stronger as the opening angle approaches 180°. We further generated a 3D viscoelastic model of fault interactions in Central North China Block and applied the finite element method to analyze the relationship between distributions of earthquakes and fault geometry. The calculated results reveal well-matched higher stress and maximum shear strain concentrations in the southern part of the Fen-wei Graben Zone than in other zones in Central North China Block, which can be explained by the longer faults, shorter center distances, shorter overlap lengths and larger opening angles. The stress distributions and fault interactions should be considered in long-term seismic hazard assessment in these zones.

Pressure‐to‐Depth Conversion Models for Metamorphic Rocks: Derivation and Applications

“…This corresponds well with the fact that the exhumation of a coherent metamorphic unit is impossible without a normal fault on top. As we have shown, stress orientation has a strong control on pressure changes, and in a complex orogen, stress orientations can vary significantly in space and time, for example, due to changes in the subduction angle or the friction along the plate boundary (Wang & Hu, 2006), the proximity to magma chambers (Gerbault et al., 2018) or faults (e.g., Martínez‐Díaz, 2002; Maerten et al., 2002; Shao & Hou, 2019), or the position within the orogen (e.g., Kastrup et al., 2004).…”

Pressure-to-depth conversion models for metamorphic rocks: derivation and applications

“…This corresponds well with the fact that the exhumation of a coherent metamorphic unit is impossible without a normal fault on top. As we have shown, stress orientation has a strong control on pressure changes, and in a complex orogen, stress orientations can vary significantly in space and time, for example, due to changes in the subduction angle or the friction along the plate boundary (Wang & Hu, 2006), the proximity to magma chambers (Gerbault et al, 2018) or faults (e.g., Martínez-Díaz, 2002;Maerten et al, 2002;Shao & Hou, 2019), or the position within the orogen (e.g., Kastrup et al, 2004).…”

Deformation analysis of a viscoelastic half-space due to a finite and an infinite interacting faults

“…He used his results to successfully explain the creep records on the San Andreas fault near Hollister, California. Shao and Guiting (2019 [17]) have discussed the interactions of fault patterns and stress fields during active faulting in Central North China Block by using numerical simulation. Attanayake et al (2019 [18]) have explained about interacting intraplate Fault Systems in Australia.…”