Low-temperature areas
Iceland's low-temperature areas lie outside the active volcanic belt that runs from Reykjanestá north across the country to Öxarfjörður. They extend from the margins of the volcanic zones across the whole country and out onto the continental shelf. Good low-temperature water can also be found within the volcanic belt — for space heating, horticulture or aquaculture.
Low-temperature exploration
Searching for hot water in low-temperature areas is about finding it as cheaply as possible, since low-temperature water competes with other heating sources. The combined cost of exploration and production must not exceed a certain ceiling over an acceptable payback period.
With changing drilling technology, ÍSOR has developed a new exploration technique known as geothermal prospecting in cold (dry) areas. It relies on numerous resistivity measurements, or on drilling many cheap 50–60 m temperature-gradient holes, to find where usable geothermal heat — preferably above 60°C — lies closest to the surface.