Role of Korteweg stresses in geodynamics

It has come to our attention that the constitutive relationship used in the modeling of geodynamical flow problems with strongly variable physical properties, should have additional terms in the stress tensor, known in the literature as Korteweg stresses (K-stresses). These stresses arising at diffuse interfaces, which can best be explained in terms of density gradients, have already been mentioned in the literature for more than one hundred years, but have not received attention recently until a combination of experimental and numerical evidence have confirmed their existence. We will discuss the important potential role these new terms have for geophysics. It has many ramifications in geodynamics, ranging from mantle convection to earthquakes and magma fragmentation.