It becomes easy to comprehend the activity of Iceland, Hawaii and Indonesia when looking at the convection cells pattern. The 2D sketch of equator plane is:
And the relevant world map of the same lines is then:
Where the lines for Iceland, Hawaii and Indonesia are marked red.
All this can be derived from one simple precondition: Stability conditions of the mantle.
Once understanding what this means, calculations can replace compiling data in many cases, saving effort and money on a grand scale.
