Drawing a continuation of the two ridges, Reykjanes Ridge and Kolbeinsey Ridge, they meet in one point. This point is also central to the elliptical form noticable of the Icelandic Shelf. This form has developed gradually, as different rift axis have been replacing each other through millions of years.
The yellow lines are the theoretical continuations of the two ridges found north and south of Iceland, until they meet at one point.
The NS axis goes right through Hekla and Eyjafjallajökull in South Iceland. In turn, Eyjafjallajökull forms a similar ‘small’ ellypse, around the same axis, as shown here:
The central point forms the crater of Eyjafjallajökull. The EW axis of the polygon connects Eyjafjallajökull and the Katla System.