Askja

Deutsch: Die Askja ist ein gro�er Zentralvulkan mit eigenem Vulkansystem im Hochland von Island. Eine bedeutende Eruption formte 1875 die letzte Caldera und den See �skjuvatn.

English: Askja is a big central volcano with nested calderas and is located in the highland of Iceland, north of Vatnaj�kull.

Fran�ais : L'Askja est un embo�tement de caldeiras en Islande, �ponyme d'un syst�me volcanique appartenant au graben m�dian et compos� de ces caldeiras, la plus interne �tant occup�e par un lac, l'�skjuvatn, du massif volcanique qui les entoure, les Dyngjufj�ll, reste d'un ancien volcan pr�c�dant la caldeira, ainsi que de volcans boucliers, de crat�res et de fissures volcaniques s'�tirant dans une direction nord-sud sur une centaine de kilom�tres de longueur. La derni�re �ruption de l'Askja remonte � la fin 1961 mais sa plus puissante des temps historiques, responsable de la formation de la caldeira remplie par l'�skjuvatn, s'est d�roul�e en 1875.

Maps

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  Location of the Askja central volcano, Iceland

Approaching Askja

Highland roads leading to Askja

F88: "�skjuvegurinn"

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Road F910

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Aerial views

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  Aerial view of the nested Askja calderas as well as lake �skjuvatn
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  Askja with the maar V�ti in the foreground

The maar V�ti

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  With �skjuvatn and Dyngjufj�ll in the background
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  With a good view of the tuff rock formations within the crater
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  The difference in water colour between V�ti and �skjuvatn is due to mineralisation, esp. higher sulfur content in the waters of V�ti
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  V�ti: easily eroded crater walls
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  Origin of V�ti: maar forming phreatomag-matic eruptions, here of the Ukinrek craters in Alaska

�skjuvatn

The origin of �skjuvatn: 1) Eruptions - Magma chamber 2) Partially empty magma chamber, 3) The roof of the magma chamber gives in and thereby the caldera is formed in a big explosive eruption.

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  Lake �skjuvatn: result of a caldera forming event
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  Probable distribution of volcanic ash during the 1875 eruption of Askja

Surroundings

Askja lies in a very remote part of Iceland, on high terrain with snow even in the summer time and deserts in the vicinity.

Drekagil

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  The canyon Drekagil
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  The huts at Drekagil:Accommodation and information for travellers
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  The huts at Drekagil

Deserts of �d��ahraun

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  Aeolian sediment transport near Askja
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  �d��ahraun with huts
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  Sandstorm south of Askja

Volcanic system of Askja

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  The fissure system of Askja is probably the longest in Iceland (about 200 km, mostly to the north of the volcanic center).
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  Magma chamber and fissure system of a similar, but different kind: at a coastal shield volcano

Eruption fissures of Askja

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  Crater rows on M��rudalshei�i
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  Eruption fissure of the Askja system
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  J�kuls�rglj�fur: A fissure of the Askja system crosses just north of Dettifoss
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  Another caused eruptions in Vesturdalur, about 2500 years ago

Lava of Askja volcanic system

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  Pahoehoe lava of Askja
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  Ropy pahoehoe at Askja
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  The formation of pahoehoe lava (here: active lava flows of Kilauea)
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  Pillow lavas of Askja: subglacial or subaqueous origin

Herðubreið: A tuya in the region of the Askja system

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  Herðubreið with snow on her top
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  Lava fields in the foreground
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  Herðubreið