Sunday, 18 April 2010

Mystery and History of Icelandic Volcanoes

The Icelandic volcanic activity has been in the news for a few days now. There had been some news too about ensuing disruptions in European air travel. However, the severity of the situation did not hit me until Saturday morning, when a friend messaged to say that due to the volcanic ash, his flight from Istanbul to Prague had been cancelled. He is now stranded in Istanbul for the next few days, living out of a suitcase that contains his belongings for what was to be a two day business trip.

I was puzzled. How could a volcanic eruption in Iceland wreak havoc in the Czech Republic? There was some impact on air traffic even in 2004 due to the eruption of Grimsvoetn, another Icelandic volcano. So what is it that makes Icelandic volcanoes so potent? I decided to follow the chronology of significant Icelandic volcanic eruptions to figure out the answer.

Iceland sits on top of the mid-Atlantic ridge, the separation between the North Atlantic and Eurasian tectonic plates, which runs from north to south of this island nation. Given its geographical positioning
[1], Iceland is a hot bed of volcanoes with approximately 130 volcanic mountains occupying the 100,329km2 land area.

One of the most interesting aspects of the Icelandic volcanoes is the submarine volcanoes that continue to form new land masses even today. Beginning 6th November 1963, scientists started detecting weak tremors at Kirkjubaejarklaustur with a likely epicentre at the southern a submarine volcano, later named Surtsey. Around the 13th /14th November 1963, the sea temperature was noted to be warmer than usual by a marine research vessel while the population of Vik (80km from Surtsey) reported the smell of hydrogen-sulphide in the air. It was on 15th November 1963 that the eruption was first spotted by a trawler on the sea in the form of dark black smoke. There were active explosions for a week, which generated a strong stream of lava that spread in the ocean and formed a land mass which measured c. 1640 ft in length and 147 ft in height. The eruptions ended only in June 1967 and the island formation concluded with the final size of the new land mass being 2.7 km2. Even before the eruptions had subsided, the first forms of life
[2] arrived on the island in 1965, in the form of moss and lichen. Then there were plants that followed, however it was not until 1975 that life on Surtsey grew, when insects were found on the island. Around 1985, seagulls began arriving on the island, carrying seeds and microorganisms and further contributing to the growth of life on Surtsey.

On 23rd January 1973 the long thought extinct Eldfell volcano, located to the south of the mainland, erupted without any warning. Close to the volcano (c. 300km away) lay the fishing town of Heimaey
[3] with a population of c. 5300. The entire city was evacuated on the first night. To save the town, the volcano fighters devised a network of pipes that were laid over the lava flow and sprayed 400 litres of seawater per second. While the wooden supports for the pipes burnt and the aluminium structures melted, the cold sea water allowed the pipes themselves to survive. Almost two thirds of the town was saved as was the entrance to the harbour. This heroic exercise was the most extensive undertaken ever in a volcanic eruption and cost about USD 1.5million at that time. By the end of the eruption that lasted 5 months, the city of Heimaey had increased 20% in size and was the proud owner of a new and naturally fortified harbour.

The most active volcano of the nation, Grimsvoetn, is covered by a glacier. On 1st November 2004, after a series of intense earthquakes, Grimsvoetn erupted. This eruption was thought to be due to the draining of a glacial lake in the volcano’s caldera. The eruption column height varied from 8-9 km up to 13-14 km. In less than two days of the first eruption, the ash had reached Norway, Finland and Sweden. There was disruption to trans-Atlantic air traffic, with KLM-Air France (then KLM Royal Airlines) suffering the maximum.

Domestic air travel in Iceland also suffered. However, within a week the eruptions subsided and there was no further interference in the aviation industry.

Eyjafjallajokull erupted on 14th April 2010, causing havoc to the global aviation industry. The fact that Eyjafjallajokull and Grimsvoetn hampered air travel but neither Surtsey nor Eldfall did is because the former two are covered by glaciers. As the hot magma spews out of the earth’s crust, it is met with cold ice which pulverizes it into tiny fragments of rock. The high temperature of the magma also causes the ice to melt and form steam. The volcanic ash is then lifted into the sky by the vast plumes of steam that are formed by the melting ice. The first eruption of Eyjafjallajokull was on 21st March 2010. However, that was not from the part of the volcano under the crater and hence there was no volcanic ash that resulted. Since the time of the Vikings, it has been observed that Eyjafjallajokull eruptions are followed by eruptions from its twin angry sister, Katla. Volcanologists warn that the five times larger Katla could spew out much more volcanic ash and increase the existing chaos.

Finding the answer to the mystery has not resulted in laying the issue of the Icelandic volcanoes to rest. My intrigue for the country has only gown. So here are some interesting facts which I thought I would share –

The word “volcano” comes from the island of Vulcano in the Mediterranean Sea off Sicily. Vulcano ts the chimney of the forge of Vulcan — the blacksmith of the Roman gods. The hot lava fragments and dust erupting form Vulcano were believed to come from Vulcan’s forge as he beat thunderbolts for Jupiter, king of the gods, and weapons for Mars, the god of war

The volcanic rock pumice is the only rock that can float in water. It is usually grey and full of bubbly holes, that form when hot gases jet furiously out of the cooling rock
The latest eruption of the Eyjafjallajokull volcano pales in comparison to eruption of Mount Skaptar in 1783, that devastated Iceland’s farming and fishing reserves, causing a famine that killed a fifth of the population

Volcanoes make sunsets more colorful. This phenomenon is because the ash particles in the atmosphere scatter the sun's rays
Nearly a third of the earth's lava output in the last 500 years has been generated in Iceland

83% of the world's sub glacial eruptions have occurred in Iceland

Volcanic ash is hard, does not dissolve in water, is extremely abrasive and mildly corrosive, and conducts electricity when wet

[1] The friction and shift between tectonic plates cause earthquakes and volcanoes. The movement of the plates towards each other pushes the liquid magma (molten rock) up and where there are cracks in the earth’s crust (called craters); this magma pours out on the surface in the form of hot liquid lava.
[3] Interesting account of eruption can be found on

1 comment:

Winnowed said...

Very interesting