In the northeastern region of Iceland, just a few kilometers east of Lake Mývatn, lies Hverir, a high-temperature geothermal area with steaming fumaroles and bubbling mud pits. It is part of the Námafjall Geothermal Field, which is one of the largest geothermal areas in the country, and the most easily accessible. This very popular tourist stop is along Route 1 (the Ring Road), and it offers a wonderful display of a unique geological phenomenon.
Upon arrival, you’ll immediately be greeted by the incredibly strong smell of hydrogen sulfide and the hissing of natural gas vents. The emergence of the gas is most apparent out of several high rock piles that were placed over old boreholes where steam emerges from deep within the earth. Past an informational sign, there is a viewing platform overlooking a large and murky bubbling mud pit. Fumarole gas rises through surface water, producing sulphuric acid, and turns the water acidic. As a result, rock and soil dissolve and produce the typical mud pots and their surroundings.
The gas and heat here are generated approximately 1,000 meters (3,280 feet) below the surface, where the temperature is above 200°C (392°F). Cold groundwater seeps down to magma intrusions, where it is superheated and returns to the surface with the gas. Sulphur deposits with mixtures of silica and gypsum then form around the vents.
There is a circular path around Hverir that allows you to safely explore the vibrant landscape. The soil in the area has little growth due to the erosion and the obvious sulfur atmosphere. Please respect the marked pathways and roped-off areas! The pits have temperatures as high as 80° to 100°C (176° to 212°F), and the soil around the edges can be unstable. Námafjall is a high mountain immediately to the west overlooking the field. There is a heated trail to the top, and many visitors choose to climb to the summit for its spectacular views of the region. From the peak, you can enjoy the incredible landscape variety of the Diamond Circle. Another trail also crosses Route 1 to the Námaskarð Pass and continues to the north.
The Bjarnarflag power station was built in 1969 to the west of Námafjall to take advantage of the area’s geothermal power. It was the first of its kind in Iceland, and it is owned by Landsvirkjun. Each year this 3-megawatt plant uses steam to generate 18 gigawatts of electricity and heating for the local district and hot water for the nearby Mývatn Nature Baths (Jarðböðin við Mývatn).