Vatnajökull glacier is the largest glacier in Europe, covering 8% of Iceland’s landmass.
It is the central feature of the Vatnajökull National park, found in the south west of Iceland, a popular spot for activities like glacier hiking from Skaftafell, boat tours in the Jökulsárlón glacier lagoon, and ice caving tours between November and March.
Vatnajökull has a surface area of approximately 8,100 square kilometres (3127 square miles); though it is rapidly shrinking due to climate change, its recession is not quite as advanced as at other glaciers, such as Langjökull and Mýrdalsjökull. In parts, it is a kilometre deep (over three thousand feet), and its average thickness is around half of that.
Vatnajökull also holds the tallest peak in Iceland beneath its ice; Hvannadalshnjúkur is 2,200 metres tall (7,218 feet). It also conceals some of the most active volcanoes in the country, the most notable being Grímsvötn, Öræfajökull and Bárðarbunga.
Volcanic activity in the region has occurred on and off throughout the centuries, and many geologists believe that several eruptions are overdue. If their calculations are correct, it would mean significant volcanic activity for Vatnajökull over the scope of the next half-century.
Depending on winds, this could result in worldwide consequences in terms of air-travel, agriculture and the general climate.
The glacier boasts over 30 outlet glaciers, which are channels of ice that flow out of ice caps but remain constrained on the sides of the valley. The major outlet glaciers of Vatnajökull include Dyngjujökull in the north, Breiðamerkurjökull, and Skeiðarárjökull to the south. To the west, one can find the outlet glaciers Síðujökull, Skaftárjökull and Tungnaárjökull.
Numerous rivers run out of Vatnajökull, making up some of the greatest glacial rivers in Iceland. The most notable are:
Jökulsá á Fjöllum (north)
Jökulsá á Brú (northeast)
Jökulsá í Fljótsdal (northeast)
Jökulsá í Lóni (south)
Jökulsá á Breiðamerkursandi (south)
Vatnajökull National Park was established in June 2008 and has slowly grown to include more and more areas. The park now covers an area of 14,141 square kilometres (5,460 square miles), 14% of the country. It is the second largest national park in Europe.
The canyon Jökulsárgljúfur was carved out by glacial floods centuries ago. At the upper end of the canyon, you'll find Dettifoss, the most powerful waterfall in Europe. Further north, the horseshoe-shaped canyon Ásbyrgi is believed to have formed when Óðinn's eight-legged horse, Sleipnir, stepped his foot down from the heavens.
East around Snæfell, one can find wetlands and ranges, home to roaming herds of wild reindeer and abundant birdlife. Steep mountain ridges make up the south side of Vatnajökull, where outlet glaciers crawl onto the lowlands. The sandy plains of Skeiðarársandur also lie to the south, and the glacial river Skeiðará runs through this vast desert.
One of Iceland's most visited landmarks in the National Park is the Jökulsárlón glacier lagoon, which sits at the base of the outlet glacier Breiðamerkurjökull. Here, large icebergs that have broken off the glacier float across a vast lake before ending up in the Atlantic Ocean, or washed ashore on the nearby Diamond Beach.
This is one of the best seal-watching spots in the country.
The volume of Vatnajökull reached its peak around 1930 but has since been in a steady process of decline. Because of rising levels of global temperature, Vatnajökull has on average lost about a metre (three feet) of its thickness annually over the past 15 years.
If temperature levels continue to rise, the glacier could be all but gone nearing the end of the next century, leaving only small ice caps on top of the highest mountain summits.
Efforts are being made to prevent what some say is the inevitable, with reforestation projects going on all around the glacier, a proven method of cooling the area. Time will tell how successful they are.
The beauty of Vatnajökull National Park has not gone unnoticed by those in film or television. Many famous scenes have been shot here, starting with James Bond: A View to Kill in 1985. Other notable films with scenes here include Batman Begins, Lara Croft: Tomb Raider, and James Bond: Die Another Day.
Most famously, however, many places in Vatnajökull have been used in the HBO Series Game of Thrones, north of the Wall. The Wall itself is constructed with CGI using shots of the glacier.