Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle‐Ductile Transition

Allison, K. L.; Dunham, Eric M.

doi:10.1029/2020jb021394

Cited by 14 publications

(10 citation statements)

References 142 publications

(265 reference statements)

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“…Additionally, heat conservation and shear heat production (shear heating), which is related to the dissipation of mechanical energy during frictional contact, is not considered. These uncoupled assumptions are frequently made in modelling of earthquake sequences [3], although the rate-dependence in rate-and-state friction empirically parameterizes some of the bulk weakening effects of temperature [22]. An elastic material behavior is assumed for the bulk, while a non-linear fault behavior is introduced using the rate-andstate dependent friction formulation as will be detailed.…”

Section: Numerical Modelling Of Earthquake Sequencesmentioning

confidence: 99%

A comparative analysis of continuum plasticity, viscoplasticity and phase-field models for earthquake sequence modeling

Goudarzi

Gerya²,

Dinther

2023

Comput Mech

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This paper discusses continuum models for simulating earthquake sequences on faults governed by rate-and-state dependent friction. Through detailed numerical analysis of a conventional strike-slip fault, new observations regarding the use of various continuum earthquake models are presented. We update a recently proposed plasticity-based model using a consistently linearized formulation, show its agreement with discrete fault models for fault thicknesses of hundreds of meters, and demonstrate mesh objectivity for slip-related variables. To obtain a fully regularized fault width description with an internal length scale, we study the performance and mesh convergence of a plasticity-based model complemented by a Kelvin viscosity term and the phase-field approach to cohesive fracture. The Kelvin viscoplasticity-based model can introduce an internal length scale and a mesh-objective response. However, on grid sizes down to meters, this only holds for very high Kelvin viscosities that inhibit seismic slip rates, which renders this approach impractical for simulating earthquake sequences. On the other hand, our phase-field implementation for earthquake sequences provides a numerically robust framework that agrees with a discrete reference solution, is mesh objective, and reaches seismic slip rates. The model, unsurprisingly, requires highly refined grids around the fault zones to reproduce results close to a discrete model. Following this line, the effect of an internal length scale parameter on the phase-field predictions and mesh convergence are discussed.

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Section: Numerical Modelling Of Earthquake Sequencesmentioning

confidence: 99%

A comparative analysis of continuum plasticity, viscoplasticity and phase-field models for earthquake sequence modeling

Goudarzi

Gerya²,

Dinther

2023

Comput Mech

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“…If any of the individual parameters in Equation 12 evolve with incremental strain or time, for example, temperature or grain size (Allison & Dunham, 2021;Montési & Hirth, 2003), then there would not be a unique relationship between 𝐴𝐴 𝐴 𝐴𝐴 and σ until a steady state is reached. The viscous creep that would result from this equilibration process is often called "transient creep," and is an important motivation for invoking Burgers rheology (Chopra, 1997;Freed et al, 2012;Post, 1977).…”

Section: Averaging Over Multiple Mechanisms and Assemblagesmentioning

confidence: 99%

On the Choice and Implications of Rheologies That Maintain Kinematic and Dynamic Consistency Over the Entire Earthquake Cycle

2022

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Viscoelastic processes in the upper mantle redistribute seismically generated stresses and modulate crustal deformation throughout the earthquake cycle. Geodetic observations of these motions at the surface of the crust‐mantle system offer the possibility of constraining the rheology of the upper mantle. Parsimonious representations of viscoelastically modulated deformation through the aseismic phase of the earthquake cycle should simultaneously explain geodetic observations of (a) rapid postseismic deformation, (b) late in the earthquake cycle near‐fault strain localization. To understand how rheological formulations affect kinematics, we compare predictions from time‐dependent forward models of deformation over the entire earthquake cycle for an idealized vertical strike‐slip fault in a homogeneous elastic crust underlain by a homogeneous viscoelastic upper‐mantle. We explore three different rheologies as inferred from laboratory experiments: (a) linear Maxwell, (b) linear Burgers, (c) power‐law. The linear Burgers and power‐law rheologies are consistent with fast and slow deformation phenomenology over the entire earthquake cycle, while the single‐layer linear Maxwell model is not. The kinematic similarity of linear Burgers and power‐law models suggests that geodetic observations alone may be insufficient to distinguish between them, but indicate that one may serve as an effective proxy for the other. However, the power‐law rheology model displays a postseismic response that is non‐linearly dependent on earthquake magnitude, which may offer a partial explanation for observations of limited postseismic deformation near some magnitude 6.5–7.0 earthquakes. We discuss the role of mechanical coupling between frictional slip and viscous creep in controlling the time‐dependence of regional stress transfer following large earthquakes and how this may affect the seismic hazard and risk to communities living close to fault networks.

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“…However, fault zone complexities, including geometric and material non-linearity (Ben-Zion & Sammis, 2003;Mitchell & Faulkner, 2009;Lewis & Ben-Zion, 2010), influence the fault slip behavior leading to complex pattern of seismicity in space and time (Chen et al, 2020;Ross et al, 2020). Physics-based simulations for sequence of earthquakes and aseismic slip (Ben-Zion & Rice, 1993;Chen & Lapusta 2009;Kaneko et al, 2010;Barbot et al, 2012;Allison & Dunham, 2021;Erickson et al, 2022;Jiang et al, 2022; are emerging as promising tools for understanding the complex processes associated with different forms of frictional instabilities and resulting slip pattern, as well as in developing seismic hazard models.…”

Section: Introductionmentioning

confidence: 99%

The Spectrum of Fault Slip in Elastoplastic Fault Zones

Mia¹,

Abdelmeguid²,

Elbanna³

2023

Preprint

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Natural faults are usually surrounded by damage zones that exhibit nonlinear material response. This study investigates the role of fault zone strength in modulating the spectrum of fault slip across different spatio-temporal scales. We carry out long-term simulations of seismic and aseismic slip for an elastoplastic spring slider model with rate-and-state friction as well as a continuum model of a 2D anti-plane rate-and-state fault embedded in an elastoplastic bulk. Results of the elastoplastic spring slider model show the emergence of a new stability boundary, depending on the bulk yield strength relative to fault frictional strength, that limits the rupture size regardless of the fault length. Continuum simulations generate a spectrum of slip analogous to the spring slider model including localized or migrating events of slow and fast slip. A fault may remain locked for yield strength sufficiently low and close to fault reference strength even if it is intrinsically rate weakening and larger than the nucleation length scale predicted by the elastic analysis. These findings shed new light on the nature of fault frictional stability and suggest the critical role of the fault zone rheological properties in modulating the spectrum of fault slip.

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Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle‐Ductile Transition

Cited by 14 publications

References 142 publications

A comparative analysis of continuum plasticity, viscoplasticity and phase-field models for earthquake sequence modeling

A comparative analysis of continuum plasticity, viscoplasticity and phase-field models for earthquake sequence modeling

On the Choice and Implications of Rheologies That Maintain Kinematic and Dynamic Consistency Over the Entire Earthquake Cycle

The Spectrum of Fault Slip in Elastoplastic Fault Zones

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