The Formation of the Atlantic Ocean

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.

The basic features shaping the Atlantic Ocean (superimposed on map from Wikipedia)

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.

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