The numerous low- and high-temperature hydrothermal systems in Iceland are the basis of a geothermal industry that supplies
space heating to 87% of its buildings and generates a third of its electric power. High-temperature systems (>180 oC) are restricted
to the neovolcanic zones of Upper Pleistocene and Holocene age (< 0.8 Myr) rifting and volcanism, where more than twenty-four
volcanoes have erupted in post-glacial time with about 20-25 eruptions each century (Figure 2). Thus the crust of Iceland has high
heat flow associated with the very frequent volcanicity, frequent seismicity, and high permeability.