Self-consistent stick-slip recurrent behaviour of elastoplastic faults in intraplate environment: A Lagrangian solid mechanics approach

Byung Dal So, Fabio A. Capitanio

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)

Abstract

Our understanding of the seismicity of continental interiors, far from plate margins, relies on the ability to account for behaviours across a broad range of time and spatial scales. Deformation rates around seismic faults range from the slip-on-fault during earthquakes to the long-term viscous deformation of surrounding lithosphere, thereby presenting a challenge to modelling techniques. The aim of this study was to test a new method to simulate seismic faults using a continuum approach, reconciling the deformation of viscoelastoplastic lithospheres over geological timescales. A vonMises yield criterion is adopted as a proxy for the frictional shear strength of a fault. In the elastoplastic faultmodels a rapid change in strength occurs after plastic yielding, to achieve stress-strain equilibrium, when the coseismic slip and slip velocity from the strain-rate response and size of the fault are calculated. The cumulative step-function shape of the slip and temporally partitioned slip velocity of the fault demonstrated self-consistent discrete fault motion. The implementation of elastoplastic faults successfully reproduced the conceptual models of seismic recurrence, that is strictly periodic and time- and slip-predictable. Elastoplastic faults that include a slip velocity strengthening and weakening with reduction of the time-step size during the slip stage generated yield patterns of coseismic stress changes in surrounding areas, which were similar to those calculated from actual earthquakes. A test of fault interaction captured the migration of stress between two faults under different spatial arrangements, reproducing realistic behaviours across time and spatial scales of faults in continental interiors.

Original languageEnglish
Pages (from-to)151-162
Number of pages12
JournalGeophysical Journal International
Volume221
Issue number1
DOIs
Publication statusPublished - 1 Apr 2020

Keywords

  • Dynamics and mechanics of faulting
  • Dynamics: Seismotectonics
  • Earthquake dyanmics
  • Mechanics, theory, and modelling
  • Rheology and friction of fault zones

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