Volcanoes in Iceland
Due to its unique geological conditions, Iceland has a high concentration of active volcanoes. Iceland has around 41 volcanic systems that can lead to volcanic eruptions. 19 volcanoes located in those volcanic systems have had several eruptions since the Vikings settled on Iceland in 874(2).
There are average volcanic eruptions in Iceland about every four years. The main reason for volcanic activities is Iceland's location on the Mid-Atlantic Ridge, and that under the island is a hot spot.
Over the past 500 years, Icelandic volcanoes have accounted for more than one-third of the total lava production on the planet. For example, the volcanic eruption in Holuhraun, north of Vatnajökull, 2014-2015, was one of the most significant volcanic lava eruptions on the earth over the past 200 years.
Volcanic eruptions in Iceland last 50 years
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Geldingadalir, Reykjanes peninsula 2021
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Holuhraun 2014 north of Vatnajökull. The eruption originated from Bárdarbunga, located beneath Vatnajökull
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Grimsvötn, under Vatnajökull 2011
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Eyjafjallajökull 2010
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Grimsvötn, under Vatnajökull 2004
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Hekla 2000
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Grimsvötn, under Vatnajökull 1998
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Grimsvötn, under Vatnajökull 1996
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Hekla 1991
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Grimsvötn, under Vatnajökull 1983
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Hekla 1981
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Hekla 1980
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Krafla, close to Myvatn on the north coast 1975
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Vestmannaeyjar 1973
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Hekla 1970
Iceland most active volcanoes
Hekla is Iceland's most famous volcano and has been for a long time, probably since the Great Eruption in Hekla 1104. Hekla's fame has been well known since the Middle Age, and many people in Europe believed that Hekla was the entrance to hell. Hekla is considered a fiery cone, even if it is spine-shaped. The mountain is very young in geological terms, It has risen over the last 7000 years, and it has therefore not been able to shape volcanic cones, but it will undoubtedly do so in the future. The Hekla volcanic system is estimated to be about 40 km long and about 7 km wide. It can therefore break out well off the mountain, and it has often happened.
Hekla is, in many ways, an unusual volcano. It has risen rapidly in modern times and is a very active volcano. The mountain also often seems to change eruption behavior. Under the mountain is a magma chamber, apparently large and layered.
Grimsvötn is a collection of lakes at an altitude of 1725 meters below Europe's largest glacier Vatnajökull. Under the lakes lies a large magma chamber to the volcano itself. Due to the volcano's heat, the constant melting of ice causes Grimsvötn lakes to get rid regularly of excess water that finds its way through natural ice tunnels down to the south coast. However. When a volcanic eruption occurs under the lakes, a violent flood eruption can occur. The year 1996, the lakes were relatively full of meltwater when the eruption began. Within a short time, the lakes became full of meltwater from the volcanic eruption. The natural ice tunnel down to the south coast was unable to accommodate all the water that was also warmer than average. The water pushed through the ice tunnel and expanded it along the way that created enormous pressure. As the water pressure approached the ice's edge to the south coast, much of the glacier burst, causing extreme flooding with large icebergs.
Floods like this know Icelandic specialists well and can foresee. The problem is that no road or bridge can stand such forces. To solve this issue, both the main road and bridges in this area are designed to make them easy to repair when the flood becomes devastating, as in 1996.
