Layered convection induced by phase transitions.

U. R. Christensen, D. A. Yuen

Research output: Contribution to journalArticlepeer-review

458 Scopus citations

Abstract

We report a systematic study on the conditions under which an endothermic phase transition can enforce layered convection. The 2- D numerical calculations of convection in a domain containing a divariant phase change were performed in the framework of the 'extended Boussinesq approximation', i.e., considering the effects of adiabatic gradient, latent heat, and frictional heating in the energy equation. We find that the critical value of the negative Clapeyron slope, which must be surpassed in order to induce layered convection, decreases in magnitude with increasing Rayleigh number Ra in the range 104= or <Ra= or <2X106. A possible superplastic rheology within the transition zone would tend to favor layered convection. Scaling the model results to the 670-km discontinuity in the Earth's mantle as a possible endothermic phase boundary, we estimate the critical Clapeyron slope to be in the range of -4 to -8 MPa/K (-40 to -80 bar/K). The possibility that the spinelrt arrow perovskite + periclase transition is within this range appears to be remote but certainly cannot be neglected.-from Authors

Original languageEnglish (US)
Pages (from-to)10,291-10,300
JournalJournal of Geophysical Research
Volume90
Issue numberB12
DOIs
StatePublished - 1985

Fingerprint Dive into the research topics of 'Layered convection induced by phase transitions.'. Together they form a unique fingerprint.

Cite this