Langjökull

Satellite image Langjökull i.d.Mi. left

Langjökull and Hvítárvatn of the Kjölur from

Hagavatn with glacier tongue Eystri - Hagafellsjökull

The Langjökull [' lauŋk ˌ joe ˑ kʏtl ˳ ] (engl. "The Long Glacier " ) is approximately 925 km ², the second largest glacier in Iceland. It is located in the western part of the Icelandic highlands. You can see it clearly from Haukadalur from where on cloudy days, the horizon line is almost indistinguishable from the ice surface.

• 2.1 Northwest volcanic system
• 2.2 volcanic system of Prestahnúkur and Geitlandsjökull
• 2.3 Volcanic activity in the Holocene

• 6.1 photos
• 6.2 Scientific contributions to the glacier
• 6.3 to volcanism
• 6.4 Sporty

Icecap Langjökull

Characteristics

This is the second largest glacier in Iceland. Such larger glaciers are called ice caps. It lies in the west of the country, covering 1989, a space of 950 square kilometers. 2006 its area was shrunk to 925 km ².

In the same year he had a volume of 195 km ³, the ice sheet was up to 580 m thick, and he lay on heights 1450-400 m.

Significantly, you can meet a variety of data relating to the amount or volume of the glacier in the literature: Old measurements were not as accurate as new, besides, glaciers are constantly changing, partly because of general climate change, in some cases, such as in Iceland, with regard for changes in the volcanic activity under the glacier.

The greatest thickness of the glacier reached in 1840.

Position and shape

The glacier follows roughly to the position of the alignment of the active volcanic zone in Iceland, to which he belongs with at least two active volcanic systems under his cap, and thus extends from southwest to northeast. He has a narrow point between the lake Hvítárvatn at the Kjölurroute and the valley glaciers Þrístapajökull that reaches down towards Eiríksjökull to the northwest.

Many mountains and mountain ranges are on the edge of the glacier, such as the volcanic mountain range Jarlhettur, which can be seen well from above the waterfall Gullfoss. In the latter, there is a Palagonitrücken, which is caused by a fissure eruption during the last ice age. More volcanic mountains are located under the glacier, where you could make out at least two calderas and Table Mountain.

Lakeside Hvítárvatn the summit Skríðufell is. Other peaks are Fjallkirkja ( 1177 m) and Hyrning (1320 m). Just east of Fjallkirkja is since 1979 a lodge of the Icelandic glaciers Association ( Jöklarannskóknarfélag ). Approximately north-west of the lake Hvítárvatn protrude the mountains Þursaborg ( 1290 m) and on Péturshorn ( 1,370 m ).

Valley glaciers

Numerous sites and valley glaciers emanate from Langjökull. The most famous of them is Geitlandsjökull ( 1395 m), one of a glacier -covered Table Mountain, which is connected to the Langjökull and projects in the southwest of it.

More valley glaciers are in the south - Vestri Hagafellsjökull and Eystri - Hagafellsjökull, the mountain Hagafell separates the two from each other, fall towards the east of the Hvítárvatn Suðurjökull and Norðurjökull between which the mountain rises Skríðufell.

Researches have shown that the valley glaciers Suður and Norðurjökull slowly advancing into the lake Hvítárvatn and reached its greatest extent about the end of the 19th century, after which they moved relatively rapidly during the 20th century back.

Water Resources and Development of the glacier

From Langjökull few rivers flow in proportion to its size. On the other hand, one has researched that large volumes of water underground and feed the lake Þingvallavatn on the Arnarvatnsheiði the Hvítá and other rivers of the Borgarfjorður. The water is until it got there as drinking water, have been around 1000 years on the road, since it fell as precipitation on the glacier.

Also the hot water of the springs in Borgarfjorður va in Reykholtsdalur, about Deildartunguhver partly comes in a roundabout way, therefore, and is heated in place by the geothermal energy.

Research can accept due to lack of nachsweisbaren sediments that about 2/3 of the flowing into the lake from the Langjökull Hvítárvatn water groundwater.

It is thought by now that if climate changes continue to evolve in the same direction as before, the Langjökull will be completely gone in about 150 years (see also: glacier shrinkage ).

Volcanism

The ice sheet Langjökull is on the WRZ ( western rift zone ) Islands, and consequently in the area of active volcanism.

At least two volcanic systems are partially under the glacier, one in the northeast and another to the southwest. The southwest has its central volcano in Prestahnúkur, other scientists also speak of Geitland volcano system, the other belongs to Hveravelir. The calderas are on aerial photographs clearly visible.

Northwestern volcanic system

The best known of these systems is the volcano of Hveravelir, which is sometimes also called the Langjökull system, it is also the name Baldjökull system. Under the glacier, a plateau is a large shield volcano and a mesa.

The volcanic system has dimensions of approximately 55 km long and 5-18 km wide.

In warm periods of the Ice Age, the volcanic system has, inter alia, give rise to some shield volcanoes in the east of present-day glacier, among other factors, 7,800 years ago the lava field Kjalhraun created, over which runs the highland road Kjölur. The high temperature region of Hveravelir part of this volcanic system. Here, the central volcano is believed by many researchers.

Crater in the west of the glacier at today Arnarvatnsheiði north of Eiríksjökull were about 1,000 years ago, the 50 km long lava Hallmundarhraun arise that extends far down into the Hvítárdalur and where the waterfalls Hraunfossar lie. Also it contains the longest lava caves discovered so far in the country, see Surtshellir.

Volcanic system of Prestahnúkur and Geitlandsjökull

In the southwest, however, the system of Prestahnúkur whose columns is also rich to below the Geitlandsjökull and Langjökull.

This volcanic system measures 70 km in length and 5-17 km in width.

On Prestahnúkur there is also a high temperature area.

Volcanic activity in the Holocene

Overall though it is a relatively quiet seen volcanic region with only about 32 eruptions in the last 10,000 years, ie after the Ice Age, which lasted longer in Iceland than on the European continent.

4-5 shield volcanoes and 5 Eruptivspalten were active after the ice age, the last column and craters in Hallmundarhraun in the 9th century.

As Eruptivprodukte are mainly basalts from the tholeitischen series mentioned. V.A. to the central volcanoes and rhyolite was unlocked.

Recent Developments in the spring of 2011

In winter 2011 a member firm of the rescue companies from the nearby town of Borgarnes that the Langjökull much more crevasses than did previously and it was therefore become quite dangerous to ride him as before.

According to the reasons for this development surveyed said the Icelandic geophysicist Helgi Björnsson, it was up one hand to the climate change. The glaciers in Iceland currently lose about 1 m in thickness over the surface distributed per year. If the climate changes were going on as, or even be made ​​worse, Langjökull would possibly not already exist in 150 years. On the other hand, the eruption of Eyjafjallajökull in 2010 had a not unimportant influence. The ash that spread across the Langjökull have, let melt it in such a way that the accumulated snow mass in 2-3 years had disappeared. Glaciers form by accumulation of snow.

Upland slopes

Access to the Langjökull consists, for example, about the Kaldidalur highland road. The highland road Kjölur leads between him and the Hofsjökull through.