Two-dimensional mantle convection simulations using an internal state variable model: the role of a history dependent rheology on mantle convection

Abstract

S U M M A R YWe apply the Bammann inelastic internal state variable model (BIISV) to a mantle convection code TERRA2D to investigate the influence of a history dependent solid mechanics model on mantle convection. We compare and contrast the general purpose BIISV model to the commonly used power-law model. We implemented the BIISV model using a radial return algorithm and tested it against previously published mantle convection simulation results for verification. Model constants for the BIISV are used based on experimental stress-strain behaviour found in the literature. After implementation we give illustrative simulation examples were the BIISV produces hardened areas on the cold thermal boundary layer that the powerlaw model cannot produce. The hardened boundary layers divert material downward giving a plausible reason for the current subduction zones that are present on the Earth.

Numerical simulation of mantle convection using a temperature dependent nonlinear viscoelastic model

“…demonstrates a comparison between vertical velocity profiles of our nonlinear viscoelastic model, power-law model (reported byChristensen (1983),Cserepes (1982),Sherburn (2011), Van der Berg (1995), Yoshida (2012)) at n=3, and the Newtonian model used byPla et al (2010). This Figure is presented in order to compare the results of current CFD simulation (based on the non-linear Giesekus consecutive equation, thermal-pressure dependence properties and depth dependence gravitational acceleration) with previous simpler simulations that used Newtonian and power-law models.…”