Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/229

 falling in the Indian Ocean. Thus great portions of the earth must have variations from the hydrostatic structure.

According to my calculations, Helmert’s result can be explained if the layer of sima 200 km. thick under the Atlantic Ocean has a density greater by 0.01 than that under the Indian Ocean. Such a condition cannot hold in the long run, and the sima will endeavour to flow in so as to restore the condition of equilibrium of the ellipsoid of rotation. A flow is, to be sure, scarcely possible with such a slight difference in density, but the ellipticity of the equator and the difference of density in the sima, and therefore, the flow, could have been of more importance in the earlier epochs.”

Without any more details, it is clear that the forces derived from Helmert’s work can render intelligible the opening of the Atlantic Ocean, for in this region the earth seems elevated and the masses will have striven to flow away to both sides.

But here yet another consideration may be adduced which might possibly be considered as an extension of Schweydar’s ideas. Such elevations of the surface of the earth above its equilibrium level naturally need not be confined to the region of the equator, but can occur everywhere on the earth. It has been shown earlier in the discussion of the transgressions and their connection with the displacements of the poles (in ), that we must expect in front of the moving pole a too high, and behind it a too low, position of the surface of the earth, and that the geological facts appear to confirm the existence of these variations. Amounts are involved, similar to those which Helmert found for the excess of the greater equatorial axis over the lesser, or perhaps double the latter amounts. In the case of the more rapid pole movements, the surface of the earth appears in front of the pole to be some