Recent earthquakes on Reykjanes Peninsula show the trend of propagating from west to east. One reason for the earthquakes is magma intrusions, and therefore we should try to understand from where the extra magma is originated. The candidate is the upwelling line of the Reykjanes Ridge. Magma flows into the tectonic plate from the division line, and then horizontally within the polygon. Rifting, aligned perpenticular to surface tectonic features, can occur within the uppermost convection rolls layer at 120 km depth (convection layer 1), due to coupling effect of the next layer below (convection layer 2). This will open the way for molten magma towards SE, until it reaches the border line between the tectonic plates within the southern half of Reykjanes Peninsula. The main two channels within the polygon are found at 1/3 of the length of the NW-side of the polygon (formed by the Reykjanes Ridge Lines), in turn forming, in the long run, the two volcanic systems of Krýsuvík and Brennisteinsfjöll. The Svartsengi volcanic area is formed due to the existence of a division line of layers 3 and 4 directly below, but the origin of intrusions there is probably also magma from the Reykjanes line.
This flow (below the Moho discontinuity) results in rising of the surface close to the border line of tectonic plates (black line). This interplay of different convection rolls layers, division of two different tectonic plates, and the resulting seismic area, creates a complicated cycle of volcanism and seismic activity, along with several geothermal sites.