Isostatic ridge elevation in a plate model
= Isostatic ridge elevation in a plate model
{title2=$h=\rho_m\alpha\Delta T a/[2(\rho_m-\rho_w)]$}
A cold linear plate profile has excess column <mass> $\rho_m\alpha\Delta T a/2$ relative to hot <mantle>. Equal <hydrostatic pressure> below the plates is restored by replacing part of the rock column with water. The displayed elevation follows to first order in <thermal expansion>; its denominator is the rock-minus-water <density> difference, not the rock <density> alone.