The Kverkfjöll mountain range is a cluster of peaks formed by a large central volcano on the northern edge of the Vatnajökull ice cap. It is the third highest mountain range in Iceland after Öræfajökull and Bárdarbunga.

Two calderas below the ice are thought to have formed part of the Kverkfjöll Ridge. The caldera to the south is covered by a glacier, but the rim of the northern caldera is now mostly ice-free except on the south side. Both lie at an altitude of around 1,800 m. The highest peak is Skarphédinstindur, 1936 m above sea level, on the eastern part of the range. The mountains are divided into eastern and western halves by Kverk, a wide pass cutting through steep, rocky walls. Kverkjökull glacier flows outwards via the pass to the north-west down to the highland plateau, which is approximately 900 m above sea level. Massive glacier tongues extend from the Vatnajökull ice cap on both sides of the Kverkfjöll Mountains, while the glaciers Dyngjujökull and Brúarjökull lie to the west and east respectively.

Ridges and rivers

Kverkfjallarani (Kverkfjöll Ridge) is made up of five or six parallel liparite ridges joining peaks that steadily increase in height as they near the Kverkfjöll Mountains. A trough, called Hraundalur, lies alongside the length of the ridge and up towards Kverk, dividing the feature into the East Ridge and West Ridge. Moraine glaciers intrude into its upper part from the eastern slopes of the mountains.

The glacial River Kreppa emerges from the western edge of the Brúarjökull glacier, while the River Jökulsá á Fjöllum is formed by many tributaries which issue from under the base of Dyngjujökull glacier. The largest of these tributaries come from just west of the Kverkfjöll Mountains, while further to the east, other tributaries disappear into the sand-scoured lava. Fine glacial clay deposits are frequently swept up by the wind, causing large mist columns which can severely restrict visibility as they sweep long distances over the countryside.

Getting to Kverkfjöll

Historical evidence and oral tradition suggest that people used to travel across the Vatnajökull ice cap in medieval times. The glacier was somewhat smaller at that time, and was in fact split in two, as the name Klofajökull (Split Glacier) seems to indicate. The route probably lay just east of the Kverkfjöll Mountains. In 1910, a German geologist named Trautz became the first person to scale these peaks.

The River Kreppa was bridged in 1970 when a track was laid via Krepputunga, across the Hvannalindir area and through the Kverkhnjukaskard pass to the Kverkfjöll Mountains. A mountain cabin was built in an old crater on the slopes of Mt Virkisfell in 1971.

Austurleid, or the East Route (F910), passes to the west of the wilderness of Ódádahraun crossing a bridge over the River Jökulsá á Fjöllum built in 1986 just south of Upptyppingar. The Kverkfjöll track (F902) branches south to Kverkfjöll. Austurleid continues east to Krepputunga where another branch (F903) leads from Kreppuháls to Hvannalindir.

Geology

The Kverkfjöll Mountains are at the eastern edge of the north-east Iceland rift and eruption zone. As is commonly the case around central volcanoes in this belt, faults run from the main volcano in a line roughly north to south. During the last Ice Age, liparite ridges and rows of peaks on eruptive fissures built up under the glacier.

The mountains extend south-west under the Vatnajökull ice cap, while Kverkfjallarani is clearly visible as a continuous row of peaks extending 30 km north-east from the mountains. They were formed for the most part in volcanic eruptions during the last Ice Age. A series of around 40 eruptions are each estimated to have emitted an average of 0.1 km³ of volcanic material.

A large number of faults split the Kverkfjallarani Ridge, where numerous lava eruptions have occurred since the ice caps melted around 10,000 years ago. The Biskupsfell eruption site and Lindarhraun lava field are believed to be the most recent, aged 1000-2000 yrs and less than 2800 yrs respectively. The eruptions have generally been effusive, and the lava appears to have flowed like rivers, leaving behind petrified falls and solidified rapids on the slopes of the tuff peaks which have been sprayed with dross and spatter.

In past eras, volcanic eruptions in the mountains and under the glaciers in this area were often followed by enormous floods in the River Jökulsá á Fjöllum.

Geothermal energy in Kverkfjöll

One of Iceland's most active high-temperature geothermal areas is located in the western Kverkfjöll Mountains. Its existence is due to a fault scarp. An area of hot springs 3 km long and nearly 1km wide can be found at an altitude of 1600-1700 m. The valley of Hveradalur lies in the uppermost and southernmost part of the area, separated from Hveraskál, or the Lower Hveradalur Valley, by the Threngsli pass, a wide gap opening to the north-west towards Dyngjujökull. Gámur, one of Iceland's most powerful geysers, is situated in the northern part of the pass. A ridge and a surface depression north of Hveraskál make up a geothermal tract named Hveratagl. A hiking trail from the Kverkjökull glacier slants up the Langafönn slope onto the ridge and along its edge to the Icelandic Glaciological Society cabin.