The mid ocean ridges can be compared with the convection rolls system. The original map looks like that:

This can be compared with the convection rolls in a simple way:

A more precise analysis, down to the 1.5° accuracy level, reveals much more, as shown for instance for the Reykjanes Ridge, barely noticeable on this World Map. The Reykjanes Ridge follows a division line exactly.
A profound difference is found between the North Atlantic Ridge and the South Atlantic Ridge. The North Atlantic Ridge is found along a up-welling line, but the South Atlantic Ridge is found in between the lines. A pattern of three ridges, for the Pacific, S-Atlantic and Indian Ocean, in harmony with the 30° divisions between convection rolls, appears,