Bárðarbunga (),árð is an active stratovolcano located under Vatnajökull in Vatnajökull National Park which is Iceland's most extensive glacier. The second highest mountain in Iceland, above sea level, Bárðarbunga is also part of a volcanic system that is approximately long and wide.
Description
Bárðarbunga is a subglacial stratovolcano under the ice cap of Vatnajökull glacier in the Vatnajökull National Park in Iceland. It rises to above sea level, making it the second highest mountain in Iceland, about lower than Hvannadalshnjúkur. The caldera is about 80 square kilometres, up to 10 km wide and about deep. The surrounding edges rise to 1,850 metres, but the base is on average close to 1,100 metres. The volcano is covered in ice to a depth of 850m, hiding the glacier-filled crater. The associated volcanic system and fissure swarm is about 190 km long and 25 km wide.
Bárðarbunga was a little-known volcano in Iceland due to its remote location and infrequent eruptions approximately once every 50 years, but recent studies have shown that many tephra layers originally thought to be from other volcanoes were ejected from Bárðarbunga.
Sustained seismic activity has been gradually increasing in Bárðarbunga and its associated northern fissure system for seven years starting in 2007 and leading to an eruption towards the end of 2014. This activity decreased after the Grímsvötn eruption in 2011, but later returned to a similar level as before the eruption. The previous eruption was in 1910. There has been frequent volcanic activity outside the glacier to the southwest in the highlands between Vatnajökull and Mýrdalsjökull, and also to the northeast toward Dyngjufjöll .
Etymology
Bárðarbunga is named after an early Icelandic settler named Gnúpa-Bárður , and literally translates as "Bárður's bulge" or "Bárður's bump" since "Bárðar" is the genitive case of "Bárður".
Eruptions and notable activity
Throughout history there have been large eruptions every 250–600 years. In 1477, the largest known eruption from Bárðarbunga had a volcanic explosivity index (VEI) of 6; there is evidence of many smaller eruptions during the past 10,000 years.
6600 BC
Þjórsá Lava, the largest Holocene lava flow on earth, originated from Bárðarbunga about 8,600 years ago, with a total volume of 21 to 30 cubic kilometres and covering approximately 950 square kilometres.
870
Many large eruptions have occurred south-west of the glacier; the first occurring since human settlement of Iceland was the Vatnaöldur eruption about 870 which had a volcanic explosivity index (VEI) of 4.
1477
The Veiðivötn eruption in 1477 is the largest known Icelandic eruption, with a VEI of 6.
1701–1864
Studies of tephra layers have shown that a number of eruptions have occurred beneath the glacier, probably in the north-east of the crater or in Bárðarbunga. There have also been smaller eruptions in an ice-free area of Dyngjuháls to the north-east. Eruptions appear to follow a cycle: there were several eruptions in the glacier between 1701 and 1740 and since 1780.
1910 eruption
1910 was the last known eruption of Bárðarbunga before the 2014 eruptions.
1996
The Gjálp fissure vent eruption in 1996 revealed that an interaction may exist between Bárðarbunga and Grímsvötn. A strong earthquake in Bárðarbunga, about 5 on the Richter scale, is believed to have started the eruption in Gjálp. On the other hand, because the magma erupted showed strong connections to the Grímsvötn Volcanic System as petrology studies showed, the 1996 as well as a former eruption in the 1930s are thought to have taken place within Grímsvötn Volcanic system.
2010
On 26 September 2010, an earthquake swarm was recorded with over 30 earthquakes measuring up to 3.7MW on the moment magnitude scale.