Iceland, Hawaii and Indonesia have special positions over the three main division lines of convection roll division lines of the Earth. This can be looked at in more and more details according to the time and effort of analysis. Let us have a look at the world map:
Not understood? This shows that Iceland, Hawaii and Indonesia have the three main division lines of the mantle convection rolls within the Earth.
Let us have a closer look at Iceland:
This drawing shows Iceland with the polar system included, main division lines darkened.
Then more accuracy can be added:
So we add this map, just to show that each line can be derived very accurately.
This is the pattern to use to make it easier to understand the volcanic activity of not only Iceland, but also Hawaii, Indonesia and all the world.
This line pattern does result from the arrangement of convection rolls within the Earth.