Looking at the equatorial pattern of distribution between land and ocean, the regularity level is almost perfect. Land occupies 30° for S-America, Africa and Indonesia, Ocean spans 60° for Atlantic Ocean and Indian Ocean. The Pacific spans 150°. This perfect distribution can be compared with the theoretical 1:1 mantle convection height to width ratio:
The accurate distribution of land masses, and how it fits to the 1:1 ratio of mantle convection compared with Earth’s layers is very convincing. Then we suddenly realize that tectonic drift must lead to rearrangement of this. But it does not mean we have to run away from this finding, hiding somewhere. That would be silly. Stop for a moment and look at the very special position of S-America, with a regularly shaped trench at one side, and the estuary of the largest river in the world at the other side, 30° apart. These settings are more developed than for Africa, with the coast located 60° east of Amazon Estuary, and the Great Rift Valley found 30° east of the western coast. One idea is that S-America has remained over the same convection roll since the time of Pangea, and Africa has moved eastwards as the Atlantic Ocean developed in between. The situation now is that the wideness of the Atlantic along equator tends to prevail as 60°. One has to study the tectonic drift vectors to realize how that happens.