The volcano Eyjafjallajökull became famous in 2010 when it erupted and airports all over Europe were closed. It is located at the western end of the mountain range of Eyjafjöll, and when revealing the mystery where volcanoes are located, the reason for the location of Seljalandsfoss becomes understandable. An EW-axis is found through Eyjafjallajökull, and the caldera of Katla as well.
The black line found on this map shows how the axis is formed from one corner of the relevant polygon to the other. Seljalandsfoss represents the end of the explicit part of fissure swarm of Eyjafjallajökull.