Kring, "The Isobaric Surface
Tensions and Thermodynamic Properties of the Surfaces of a Series of Normal-Alkanes, C-5 to C-18, 1-Alkenes, C-6 to C-16 and of Normal-Decylcyclopentane, Normal-Decylcyclohexane and Normal-Decylbenzene," J.
The surface of the sea is considered to be an isobaric surface.
9 Although we usually measure height on land against sea-level, the sea is not in fact strictly flat, but has its own topography that is generally measured in terms of the difference in height and the isobaric surface at a specific reference pressure.
The effect is due to the deformation of Acadian isothermal and isobaric surfaces
by the antiform al cross-fold, and does not represent a true syn-metamorphic inversion.