Glaciers in Iceland
Glaciers cover about a tenth of Iceland and are one of the country's defining features. They store enormous amounts of fresh water, shape the landscape and feed the largest rivers. In recent decades Icelandic glaciers have retreated rapidly because of a warming climate.
The largest glaciers
Iceland has about 270 named glaciers, but the vast majority are small. The five largest are ice caps in the highlands that cover mountains and volcanoes.
| Glacier | Area (approx.) | Height | Note |
|---|---|---|---|
| Vatnajökull | 7,700 km² | 2,110 m | Europe's largest glacier by volume outside the polar regions |
| Langjökull | 850 km² | 1,450 m | Ice tunnels have been dug into the glacier |
| Hofsjökull | 810 km² | 1,765 m | A large volcano with a caldera lies beneath it |
| Mýrdalsjökull | 520 km² | 1,493 m | Covers the Katla volcano |
| Drangajökull | 140 km² | 925 m | The only glacier in the Westfjords |
| Eyjafjallajökull | 70 km² | 1,651 m | Famous after the 2010 eruption |
| Snæfellsjökull | 10 km² | 1,446 m | Setting of "Journey to the Centre of the Earth" |
Area figures are rounded and are decreasing year by year.
Vatnajökull
Vatnajökull is by far the largest glacier in the country and covers about 7% of Iceland. It is generally 400–600 metres thick and up to about 950 metres at its thickest. Several active volcanoes lie beneath the ice, including Grímsvötn, Bárðarbunga and Öræfajökull. Dozens of outlet glaciers flow from the main ice cap, such as Skeiðarárjökull, Breiðamerkurjökull, Skaftafellsjökull and Dyngjujökull. Vatnajökull is the heart of Vatnajökull National Park, which was added to the UNESCO World Heritage List in 2019.
Jökulsárlón and other glacial lagoons
Jökulsárlón at Breiðamerkurjökull is the best-known glacial lagoon in Iceland. It began to form around 1934–1935 as the glacier retreated and is now the deepest lake in the country, over 250 metres deep. Icebergs that calve from the glacier front drift across the lagoon and are carried down a short river to the sea, where the surf washes them onto the black sand – a spot often called Diamond Beach. Nearby is Fjallsárlón, smaller but no less impressive.
Glacial outburst floods
A jökulhlaup is a sudden flood that occurs when water bursts out from beneath a glacier. Floods can be caused by subglacial eruptions or by geothermal heat melting the ice so that water collects in lakes, as at Grímsvötn and the Skaftá cauldrons. The Icelandic word jökulhlaup is used as a scientific term in English and many other languages. In the great flood on Skeiðarársandur in 1996, the discharge reached about 45,000 cubic metres per second and bridges on the Ring Road were swept away.
Glacier retreat
Icelandic glaciers have retreated considerably since the end of the Little Ice Age in the late 19th century. Since 2000 they have lost about 7–8% of their area. Glaciologists predict that unless warming is slowed, most Icelandic glaciers will largely disappear within the next 100–200 years. In 2014 Okjökull, on the Kaldidalur route, was officially declared no longer a glacier. In 2019 a memorial plaque was unveiled there, with a letter to the future by the writer Andri Snær Magnason.
Glacier tours and safety
Glacier hikes and ice cave tours are among the most popular activities for visitors, especially on Sólheimajökull, Svínafellsjökull and in Vatnajökull National Park. Glaciers are dangerous, however: they hide crevasses and moulins, and the weather can change suddenly. Never go onto a glacier without an experienced guide and proper equipment such as crampons, an ice axe and a rope.
Frequently asked questions
What is the largest glacier in Iceland?
Vatnajökull is the largest, about 7,700 km², covering about 7% of the country.
What is a jökulhlaup?
A jökulhlaup is a sudden flood when water bursts from beneath a glacier, often because of an eruption or geothermal heat under the ice.
Can you visit an ice cave in Iceland?
Yes. Ice caves form in the outlet glaciers of Vatnajökull in winter and can be visited with a guide from about November to March.