Linear stability analysis of the onset of sublithospheric convection

Citation:
Landuyt, W, Ierley G.  2012.  Linear stability analysis of the onset of sublithospheric convection. Geophysical Journal International. 189:19-28.

Date Published:

Apr

Keywords:

asthenosphere, couette-flow, Dynamics of lithosphere and mantle, Earth, generation and transport, heat, instabilities, Instability analysis, mantle, oceanic lithosphere, Small-scale convection, thermal-convection, variable viscosity

Abstract:

We consider the onset of small scale convection associated with the cooling of the oceanic lithosphere. This process is investigated by examining the linear stability of a 2-D shear flow that is cooled from the top and obeys an Arrhenius rheology. The perturbation equations are derived assuming a parallel flow, local 1-D analysis. The linear stability results are able to reproduce the structure and growth rate produced by solving the full non-linear equations. In addition, linear stability analysis predicts a similar dependence of onset times on activation energy and Rayleigh number as previous studies when small plate velocities are specified. Our linear stability analysis predicts a significant increase in the onset time with increasing plate velocity. Suggestions are given for the dynamical influence of plate velocity in reducing the convective forcing and delaying onset times.

Notes:

n/a

Website

DOI:

10.1111/j.1365-246X.2011.05341.x