Langisjór is a world of its own, and so important to geology. As it is a very long feature, about 20 km, it shows the main alignment of the relevant volcanic zone quite well. The world’s mantle convection cells are arranged according to the formula used here, and it is exhibited quite clearly at Langisjór:
The accuracy is a proof that this is the correct way to compare surface features with the system of convection currents underneath, as shown in a previous post about Langisjór.