Volcanic activity in South Iceland

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Before all the Bárðabunga activity there were talks regarding increased activity in Hekla.  We summarised the volcanic activities in the south of Iceland.
But talks about eruption in Hekla have been going on since 2006, when a tiny earthquake and some surface swelling hinted that new magma had accumulated. Media has warned of similar things in Hekla in 2011 and 2013 with out any eruptions.

Hekla is the 2nd most active volcano in Iceland, first being Grímsvötn. She has erupted approximately every 55 years. An active volcano for centuries, the mountain Hekla is one of the most famous in the world. Old tales tell of the belief that the souls of the condemned travelled through Hekla’s crater on their way to hell.

The whole mountain ridge of Hekla is about 40 km long. The fissure which splits the mountain ridge is about 5,5 km long. The mountain is about 1491 m high.

It is thought that Hekla has had at least twenty eruptions since the settlement of Iceland. The biggest eruption was in 1104. Hekla has erupted four times in the 20th century, the last time in February 2000 and the eruption lasted for two weeks.

Over the past 7000 years Hekla has had five big fissure eruptions. The biggest eruptions were 4000 and 2800 years ago. Traces of these two eruptions can be found in the soil in the North and the North-East of Iceland. The biggest layer of tephra from one eruption fell in the eruption 2800 years ago. It covers about 80% of the country and its volume was around 12 cubic km. Traces of it has been found in various places in Scandinavia.

They are the third biggest volcano activity in the world.  Skaftáreldar – The largest documented volcanic eruption in Iceland after settlement was in the years 1783-84 when a huge ridge of eruption opened, the ridge was 25 km long and had about 100 erupting craters. This took place in south Iceland and is always referred to as the Skaftár fires. From this eruption Iceland had its third biggest lava flow for the past 10.000.  It covered over 565 fm2, 14 farms in 4 counties went under lava and 30 other farms where severely damaged. Because of these eruptions 80% of Iceland’s sheep stock, 75% of the horse stock and 50% of the cattle stock was killed. Do to these huge eruptions a very hard time started in Iceland, a huge mist covered big part of Iceland and caused colder weather, hunger and suffering among the Icelandic nation. About 20% of the Icelandic nation died because of this.   The year after an earthquake shook Iceland and made things even worse. The aftermath of the Skaftár fires were very severe: sour rain all over Europe, dark and cold days, some say it is the source of the french revolution in 1789.

Katla – The volcano Katla, in the Myrdalsjokull glacier, has erupted on average every 40 – 80 years. Sixteen eruptions have been recorded since the settlement of Iceland, the last in 1918, ( 1955 -2000?)but there have probably been more, perhaps 20 in all. Katla is one of the most famous volcanoes in the country, and its eruptions usually have very serious consequences; the glacier above the volcanic vent melts and the melt-water collects under the ice cap until it makes its way out under the edge in a violent flood. These are called “Jokulhlaup”. Huge amounts of ice ( size of Skógarfoss) and sand carried along by the floodwater, and anything in the path of the flood tide is destroyed. Deposits in past floods have formed most of the Myrdalssandur sand plain.  Part of Vík in Mýrdalur stands on a land fill from Katla floods, the sea shore near vik is disappearing due to the sea, there is talk of building protective walls  but they will be very expensive and when Katla erupts, they will no longer be needed as she will add so much to the land.

Vestmannaeyjar –The Westman Islands are a group of fifteen islands, situated just off the south coast of Iceland. At 2am on the night of January 23rd 1973, a massive eruption began in the eastern part of Heimaey. Almost all of the 5,000 inhabitants were safely evacuated to the mainland. The eruption lasted for over 5 months and caused extensive damage to the town, burying houses under lava and ash. Only a few weeks after the eruption ended, the population had returned to clean up and continue their lives.

Surtsey The new island was named after Surtr, a fire jötunn or giant from Norse mythology is not only one of the world’s newest islands, but the most filmed and researched and one of the most restricted. Ever since the eruption in 1963 which heaved it up out of the waters 18km (11 miles) south-west of Heimaey, its progress has been monitored giving scientists a fascinating insight into how a new island evolves, how flora and fauna develop and so on. Because of this very few people are allowed to visit the island, and special permits are only granted for scientific research. These scientists are studying how the flora and fauna develops, so the have to be very careful not to disturb anything while they are there. One day when the go to the island they find a tomato plant!  Thats weird a tomato plant on Surtsey. The start following the root of the plant and it leads them to a rock, and under the rock there is human shit, some of the scientist obviously ate a lot of tomatoes. or as Wikipedia puts it: an improperly handled human defecation resulted in a tomato plant taking root which was destroyed.

When the eruption first occurred, columns of ash were sent almost 9,146m (30,000ft) into the sky and could be seen on clear days as far away as Reykjavík. The birth of Surtsey took almost four years as eruption followed eruption until 1967, by which time the island stood 150m (492ft) above sea level and covered an area of almost 3sq km (2sq miles). Because of pounding seas, there was a considerable amount of early erosion, but the island core quickly solidified as rock and is now holding its own while scientists watch everything.