The dormant Thrihnukagigur volcano last erupted over 4.000 years ago. There are no indications of it erupting again in the nearest future. The volcano’s name, mostly unpronounceable for other than locals, would be directly translated to English as “Three Peaks Crater”. The name comes from Árni B. Stefánsson, who was the first to explore the vault and has pleaded the case of making it accessible for years.
The three craters (one of which you will be decenting into) are prominent landmarks, standing against the sky on the highland edge, about 20 km (13 miles) southeast of the capital area within the protected area of Bláfjöll Country Park The most northeasterly of the three peaks is a small cinder cone, standing about 35 m (100 ft) higher than its surroundings. In the top of this cone is a funnel shaped opening, about 4×4 m (12×12 ft) wide, the entrance of a huge 120 m (400 ft) deep, bottle-shaped volcanic vault, measuring 50 x 70 m (160 x 220 ft) at the bottom. Volcanic passages continue down to the southwest, to a total depth of about 200 m.
The beauty of the crater mostly consists in the various colourations found inside it and its enormous and, to some extent, intimidating size. In context, the ground space is equivalent to almost three full-sized basketball courts planted next to each other and the distance from top to bottom is a little short of three NYC’s Statue of liberty planted on top of each other. The full sized statue even fits well into the chamber.
Make no mistake – It’s huge!
One of a kind magma chamber
The magma chamber, which you will be descending into, is often referred to as the heart of a volcano. It’s there where the liquid rock awaits to find a way through the surface, causing a volcanic eruption. In most cases, the crater usually closes after the eruption with hard cold lava.
Thrihnukagigur volcano is a rare exception of this, being a case where the magma in the chamber seems to have disappeared. It’s believed that the magma solidified through the walls or quite simply went back to the depths of the earth.