As magma is entering the brittle crust with a flow rate of perhaps about 20 cubic meters per second, a dyke is forming in the southern half of the Reykjanes Peninsula. Geoscientists are therefore in the difficult position of explaining what is going on, and at the same time trying to predict what will happen. No one can foresee an eruption, but different scenarios are studied. Here I will show you a simple map with the main features. Convection rolls model divisions are marked with red lines. The tensional vectors are parallel to those lines. A red arrow indicates the present scope of the dyke being formed. Information from the Icelandic Met Office is found here: https://www.vedur.is/um-vi/frettir/skjalfti-m57-a-reykjanesi

We are aware that, where the dyke has already formed, the magma might make its way upwards. The triggering effect might be extra heat entering the dyke, and that might originate from the convection rolls division lines found south-west of it. As the dyke propagates farther in that direction, the more likely it is that an eruption will occur according to this model. In 2014, the Holuhraun eruption started under similar circumstances.