Small Melt Effect

The small melt effect is the parametrization of the melt-correction factor of Holtzman, B. K. (2016), “Questions on the existence, persistence, and mechanical effects of a very small melt fraction in the asthenosphere”, Geochem. Geophys. Geosyst., 17, 470– 484, DOI.

By default, the melt-correction factor is turned off by the VBR.in.GlobalSettings.melt_enhancement flag. To turn it on, set VBR.in.GlobalSettings.melt_enhancement=1 before calling VBR_spine(). The strength of the melt enhancement is controlled by phi_c and x_phi_c in the flow law parameter structures (e.g., VBR.in.SV.HZK2011.diff.phi_c) but those fields are only used when VBR.in.GlobalSettings.melt_enhancement=1.