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Toward Robust and Predictive Geodynamic Modeling: The Way Forward in Frictional Plasticity
Author(s) -
Duretz Thibault,
de Borst René,
Yamato Philippe,
Le Pourhiet Laetitia
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl086027
Subject(s) - plasticity , geology , rheology , shear (geology) , viscoplasticity , tectonics , shear band , mechanics , geophysics , seismology , physics , finite element method , petrology , constitutive equation , thermodynamics
Abstract Strain localization is a fundamental characteristic of plate tectonics. The resulting deformation structures shape the margins of continents and the internal structure of tectonic plates. To model the occurrence of faulting, geodynamic models generally rely on frictional plasticity. Frictional plasticity is normally embedded in visco‐plastic (V‐P) or visco‐elasto‐plastic (V‐E‐P) rheologies. This poses some fundamental issues, such as the difficulty, or often inability, to obtain a converged equilibrium state and a severe grid sensitivity. Here, we study shear banding at crustal‐scale using a visco‐elasto‐viscoplastic (V‐E‐VP) model. We show that this rheology allows to accurately satisfy equilibrium, leads to shear band patterns that converge upon mesh refinement, and preserves characteristic shear band angles. Moreover, a comparison with analytic models and laboratory data reveals that V‐E‐VP rheology captures first‐order characteristics of frictional plasticity. V‐E‐VP models thus overcomes limitations of V‐P and V‐E‐P models and appears as an attractive alternative for geodynamic modeling.