HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Modelling lithospheric deformation using a compressible visco‐elasto‐viscoplastic rheology and the effective viscosity approach

Abstract : Deformations of the colder regions of the lithosphere mainly occur in the frictional regime. In geodynamic models, frictional plastic deformations are often highly localised (shear bands) and are used as proxies for faults. However, capturing the generation and evolution of shear bands in geodynamic models is troublesome. Indeed, mesh dependency and lack of convergence affect, to some extent, the results of geodynamic models. Here we extend the most common plasticity implementation used in geodynamic codes (effective viscosity approach) to include the combined effects of elasto-plastic compressibility, plastic dilatancy, strain softening and viscoplasticity. The latter acts as a regularisation that cures most of the known issues of geodynamic models related to frictional plasticity. Using regularised models based on the M2Di MATLAB routines, we show that volumetric elasto-plastic deformations can significantly impact crustal-scale shear banding. We also show that the artificial overstress caused by viscoplasticity can be mitigated by employing power-law models. Furthermore, we demonstrate that plasticity algorithms common in geodynamics (based on the effective viscosity approach) can be as accurate as those obtained with algorithms typically used in engineering (return mapping with a consistent tangent operator). Finally, we show examples of long-term tectonic deformations using the state-of-the art geodynamic code MDoodz. They indicate that viscoplastic regularisation can be used efficiently to obtain reliable simulations in geodynamics.
Document type :
Journal articles
Complete list of metadata

Contributor : Isabelle Dubigeon Connect in order to contact the contributor
Submitted on : Monday, July 12, 2021 - 10:26:01 AM
Last modification on : Wednesday, May 11, 2022 - 4:25:20 AM
Long-term archiving on: : Wednesday, October 13, 2021 - 8:16:02 PM



Thibault Duretz, René Borst, Philippe Yamato. Modelling lithospheric deformation using a compressible visco‐elasto‐viscoplastic rheology and the effective viscosity approach. Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2021, 22 (8), pp.e2021GC009675. ⟨10.1029/2021GC009675⟩. ⟨insu-03283712⟩



Record views


Files downloads