Geothermal heat at Hágöngur

Hágöngur is about 40 km north-east of Þórisvatn. In this area there is a little-known high-temperature area that partly ended up under Hágöngulón. In the area there appears to be a central volcano, and it is not unlikely that there is a caldera in it although it is not visible. Rhyolite formations indicate this, lining up in a half-arc (including Nyrðri- and Syðri-Hágöngur).

Surface geothermal heat is first and foremost in three places, and two of them ended up under water when Hágöngulón was filled. The third place is westernmost in Sveðjuhraun. Cold, older alteration has been found over quite a large area, especially at Kvíslarhnúkar north-east of Hágöngulón but also at Hágöngur themselves.

Resistivity measurements indicate that the geothermal area is 28-50 km2 in size, and the chemistry of the steam that rises up indicates about 300°C temperature in the deep system.

Source: Haukur Jóhannesson, ÍSOR.