The Atlantic Ocean is mainly formed by two gigantic convection rolls. In between them, the Mid-Atlantic Ridge actively forms new oceanic crust out of basalt. The North and South Atlantic look similar, and here we will have a look at both the similarities and the differences. There are four main sections with 32° interval from north to south.
Within part 1, the ridge and rolls division line are unified along Reykjanes Ridge (offset by 1.5° west), but sways east of the convection rolls division line south of the Reykjanes Ridge. Both ridge and convection rolls division line intersect each other at 32°N. The reason is that at 32°N the convection rolls are oriented directly NS, so it becomes a latitude of division between different sections of the ridge.
Within part 2, the ridge sways slightly west of the convection rolls division line. A part of Africa still sticks out into the Eastern Convection Roll Area within that section.
Within part 3, the ridge is almost directly oriented NS, giving the South Atlantic part a slightly different appearance than the North Atlantic. The section includes the highland of Southern Africa, marked by the outer limits of the convection roll. At 32°S, the eastern division line crosses the coastline.
Within part 4, the Ridge makes a turn towards east. The arc shaped ridge makes the turn around the convection rolls division line, also marking the end of the real Mid-Atlantic Ridge.
It is notable that the western foothold point of Greenland at 64°N is of the same nature as the eastern foothold point of Africa at 32°S.
In this way, we get a glimpse of the main constraints forming the Atlantic Ocean during the present era. A NS-axis can be marked from equator to Iceland and through the South Atlantic. This NS-axis is the same as can be found when examining the details of Icelandic geology, both volcanic activity and the Icelandic Plateau.