The plates are drifting apart approximately 2,5 cm every year. This movement results in volcanic activity as well as earthquakes. As the ridge stretches through Iceland, the presence of these is prominent. The oldest parts of Iceland are the north-west and the east. The utilisation of the geothermal resouce does not only depend on the heat or the high temperature.
Water plays a significant role, being the heat-carrying media.
Thus, geothermal science is strongly related to the hydrogeology of Iceland. As precipitation filters through the formations, water reaches the hot source. If the fluid has easy access to the surface again, it may be found in warm springs. The tectonics play a significant role in this respect, as fractures and fissures are very important for the water bearing features of the geothermal areas. In this respect, like it or not, earthquakes keep the geothermal systems alive, by preventing the cracks to be plugged or blocked, f.ex. by scalings.