Vatnajökull

Vatnajökull, satellite image from NASA

The Breiðamerkurjökull, one of the outlet glaciers of Vatnajökull

The Vatnajökull [' Vahtna ˌ joe kʏtl̥ ˑ ] ( Isl " glacier water " ) is the largest glacier in Iceland and also outside the polar region and the largest in Europe. The plateau glacier is located in the southeast of the island. Its area is about 8,100 km ², which is about 8% of Iceland's surface. The ice volume is estimated to be over 3,000 km ³.

• 3.1 Outbreaks of Grímsvötn
• 3.2 glacier run on Köldukvíslarjökull
• 3.3 Overview of volcanic eruptions volcanic systems under the Vatnajökull since the settlement of Iceland

• 7.1 images
• 7.2 Scientific. article 7.2.1 General for Vatnajökull
• 7.2.2 To Glaciology
• 7.2.3 The volcanic systems under the Vatnajökull
• 7.2.4 individual aspects

Geography

The thickness of the ice layer is up to 900 meters. Some of the most active volcanoes on the island are under the glacier and between them about 500 to 800 m deep valley. Since September 12, 2004 on 50 % of Vatnajökull are in Skaftafell National Park. On 7 June 2008, the area of the glacier was incorporated into the newly established Vatnajökull National Park, which is now the largest national park in Europe. In the south of the Vatnajökull National Park is the Morsárfoss, the highest waterfall of Iceland.

From Slættaratindur, the highest mountain in the Faroe Islands, you can see the Vatnajökull allegedly over a distance of 550 km for best visibility. This would be according to the Guinness Book of Records the longest sight on earth, but is sometimes doubted.

Glaciology

Origin and growth of the glacier

Like many other glacier in Iceland was the Vatnajökull about 2,500 years ago.

At the time of the Hungarian conquest in the 9th century AD, the glacier was much smaller than today. So were about the Esjufjöll (not to be confused with the Esja in Reykjavík ) outside the actual glacier, while they are now in the middle.

In the 15th century, the so-called Little Ice Age, which lasted until about 1890 in Iceland began. The Vatnajökull grew as a result.

Reduction of the ice

For several years, the Vatnajökull loses like most glaciers in size, to be exact since the end of the 19th century by 10 %, ie about 300 km ³, which means a contribution by 1 mm to the current rise in sea. Possible reasons are global climate change (greenhouse effect ), and the volcanic activity in recent years - the volcanoes lying under the glacier and Grímsvötn Bárðarbunga among the most active of the island - led ( see also glacial retreat ).

In direct connection with this, there is also the increase of the country. The severity of the ice cap that weighs on the country decreased. As a result, raises the affected country in the last 100 years in the middle of Vatnajökull by about 100 m, at the edges by about 50 m, in Höfn í Hornafirði to 20 m and at a distance of 50 km from the glacier after all, even to about 5 m.

Volcanic activity

The highest elevation 2,110 meters above sea level with Iceland, the volcano Hvannadalshnjúkur, located in the south of Vatnajökull.

Under the ice sheet of Vatnajökull there are apart from this mountain there are several other active volcanic centers (see subglacial volcano).

In the West would have to call the Grímsvötn, the most active volcanic system in Iceland. Gjálp is often seen as part of the same, but sometimes as a separate volcanic system. In the north of Vatnajökull are Bárðarbunga to their system and also Kverkfjöll, in the southeast Esjufjöll and Öræfajökull / Hvannadalshnúkur. In addition, geologists reckon Loki Fögrufjöll (also: " Hamarinn " or " Lokahryggur " ) ( in the west) and Pálsfjall ( in the southwest of Vatnajökull ) to the central volcanoes beneath the Vatnajökull. Magnús Tumi Guðmundsson expects the system to the Grímsvötn central volcano and the smaller Þórðarhyrna, which the Bárðarbunga the HamarinnEin of further high-temperature system with intrusion boilers located west of Grímsvötn, the Skaftárkatlar. Among the boilers each collected at a rate of 3 years up to once a year condensation, which similar to the Grímsvötn finally breaks through an ice barrier and flows over the river Skaftá into the sea. But this glacier runs have usually only a fairly small scope 400-1500 m³ / sec But because they can grow very quickly and may carry toxic gases to the Skaftárkatlar be well monitored.

Bárðarbunga last erupted in September / October 1996 the Grímsvötn last in May 2011.

Outbreaks of Grímsvötn

On 1 November 2004, an outbreak took place at the Grímsvötn, who sent a flood upon the Skeiðarársandur. The flood came, however, in no way to the flood of 1996 and amounted to approach their peak only 2,000 m³ / sec The region did not have to be evacuated during this eruption. Only the air traffic was partially diverted. On 3 November, the eruption were detectable in Finland ash particles.

Another eruption of Grímsvötn occurred on May 21, 2011.

Glacier run on Köldukvíslarjökull

On 12 and 13 July 2011 is presented tight tremor at the volcano Loki Fögrufjöll, where a glacier run followed from the belonging to the Vatnajökull glacier side Köldukvíslarjökull over the river Sveðja. This was mostly collected from the dam Hágöngulón, the water level in the 37 km ² lake by 70 inches anstieg.Die amount of liquid was estimated at 26 gigaliters. At its peak between 2 und 4 clock clock on the night of July 13, 2011 streamed over 2,000 m³ / sec in the reservoir .. During an overflight of the glacier we put on Hamarinn set a newly created break- boiler in glacial ice. On a return flight over the glacier on July 18, 2011 Scientists found two new boilers and slump brought on Hamarinn measuring instruments. Also took one sample from the water of the river Sveðja to investigate whether the glacier run would be to frost up by the newly discovered high-temperature area at Hamarinn, where the water had collected only in a subglacial lake and then broken through after reaching a critical mass, or was due to a subglacial volcanic eruption.

Overview of volcanic eruptions volcanic systems under the Vatnajökull since the settlement of Iceland

Numerous volcanic eruptions can only guess, since their power was not enough to defrost the up to 900 m thick glacier above you and they were felt only over glacial cycles. The overview I.A. follows Representations of the Volcanological Institute of the University of Iceland ( Institute for Earth Sciences )

Vatnajökull National Park

( See main article Vatnajökull National Park )

Since 2008, the Vatnajökull National Park. It covers 12,000 km ², or 12 % of the land surface. The Vatnajökullgletscher is in it as well as the former Skaftafell National Park, the Jökulsárgljúfur National Park and the Laki craters. It is divided into a northern, southern, western and eastern area.