Don't wake up the "angry sisters"

A period of volcanic activity begins on the island of Iceland

A volcanic eruption in Iceland has changed the way life is lived in Europe. So far, the eruption of the Eyjafjallajokull volcano, which means “island of mountain glaciers” in Icelandic, has only led to the closure of airspace over most of the Old World. Meanwhile, this is not the first time that a volcanic eruption on the small island of Iceland has seriously affected the whole of Europe.

Iceland is often called the island of ice and fire. Glaciers occupy 10% of the country's territory. When it comes to fire, Iceland ranks among the top on the planet when it comes to volcanic activity. Over the past 500 years, Icelandic volcanoes have erupted a third of all the lava on the planet. There are 35 active volcanoes on and around the island; in total, there are over 130 volcanoes in Iceland. On average, seismologists have calculated, an eruption occurs every five years.

Increased volcanic activity is explained by the island’s location on the Mid-Atlantic Ridge, which marks the boundary between the Eurasian and North American plates. Most of the volcanoes are located along this border, which crosses Iceland from southwest to northeast.

The significantly increased frequency of eruptions on the island suggests that the region is entering a phase of increased volcanic activity. Scientists have calculated that over a 40-year period of high volcanic activity, the Gremsvotn and Berdarbunga volcanoes erupt 6-11 times, and during the same period of calm, no more than three.

The period of increased activity, seismologists believe, may last up to 60 years, and the peak will most likely occur in 2030-2040. So now the Icelandic volcanoes are just waking up from their sleep and starting to “warm up”.

The cyclical nature of volcanic activity was proven in 1988 by Gudrin Larsen, a professor of geology at the University of Reykjavik, who, together with his colleagues, collected and analyzed samples of lava, ice and documents from historical archives over 800 years. Periods of increased activity follow periods of relative decline. The second half of the last century was quite calm.

There is also an increase in seismic activity. In May 2008, Reykjavik shook quite violently. The force of the tremors reached 6.1 on the Richter scale.

The fact that Icelandic volcanoes are gradually waking up to life is also evidenced by the fact that the Eyjafjallajokull eruption, which began on March 21, practically coincided with another eruption. The Fimmvereuhels volcano woke up from hibernation on March 20, there was a lull on April 12, but on April 15 the eruption resumed with renewed vigor.

Eyjafjallajokull is located on the southeast coast of the island. The volcano, whose eruption caused so much noise last week and which has already covered the entire north of Europe with ash, is “baby” by Icelandic standards, despite the fact that its previous eruption lasted over a year: from December 1821 to January 1823. In addition, it also erupted in 920 and 1612.

The eruption of Eyjafjallajokull has attracted increased attention not so much due to the fact that it has already closed the airspace over most of Europe for several days, but rather due to the fact that its awakening, as follows from history, usually precedes the eruption of Katla, one of the most large Icelandic volcanoes, located 12 km from it. At least in the past, Katla has erupted three times following Eyjafjallajokull. One can only hope that the sequence doesn't work this time, because Katla, one of the two so-called "angry sisters," has shown no signs of unusual activity this year.

Katla is located under the huge Mýrdasjökull glacier. It is one of the highest volcanoes in Europe (1512 m) with a crater with a diameter of about 10 km. The danger of an eruption of this volcano is, as you might guess, that as a result the ice can melt and cause severe flooding. If an eruption occurs, you will have to act very quickly. In 1918, when Katla's last major eruption occurred, flooding began within an hour of the first clouds of smoke appearing over the crater.

Icelanders call the second “angry sister” the famous Hekla (1490 m), this is the most seismically active volcano on the island. In the Middle Ages it had a more expressive name - “Gateway to Hell.” It was believed that it was through her that the souls of sinners fell into the underworld.

By the way, it is no coincidence that the French science fiction writer Jules Verne sent the heroes of his novel “Journey to the Center of the Earth” through the crater of an extinct volcano, not just anywhere, but in Iceland.

Despite the fact that the second half of the last century was relatively calm in Iceland, it was not without strong eruptions. A major eruption occurred in 1973 near the main fishing port of Iceland, Vestmannaeyar, located in the south of the country, on the island of Heimaey. An unexpectedly formed crack 1.5 km long cut the island into two parts. Lava poured out of it for five months, destroying almost 400 houses. In place of the meadow, a hill 200 m high was formed. The entire population of the island, which is almost 5.5 thousand people, had to be urgently evacuated to Iceland.

Volcanoes erupt not only on land, but also in the sea near Iceland, especially off its southern coast. Volcanic activity off the coast of Iceland leads to the appearance of volcanic islands. For example, Sartsi was formed as a result of the eruption of an underwater volcano in 1963.

Icelandic volcanic eruptions have long been poisoning the lives of Europeans in the truest sense of the word. For example, Scottish scientists believe that the ash that fell in Scotland as a result of a strong eruption in Iceland in 1695 caused “sulfur mists” and severe famine in the north of the British Isles.

As a result of further explosive expansion of the steam, the magma turns into tiny particles of ash. When it enters the atmosphere, it retains the sun's rays, which negatively affects the growth of plants, incl. and agricultural crops.

In addition to ash and dust, sulfur dioxide also rises into the air as a result of the eruption. This toxic substance, once in the upper layers of the atmosphere, turns into droplets of sulfuric acid, which, like a veil, covers the Earth from the sun's rays.

However, the eruptions of the late 17th century cannot be compared in either strength or consequences with what happened almost a century later, when natural disasters in Iceland echoed loudly throughout the Northern Hemisphere.

We are talking about the eruption of the Laki volcano, or Lakagegara (1725 m), located in the southeast of Iceland, near the Eldgja canyon and the town of Kirkjubøyarklaustur, and the concurrent eruption of the Gremsvötna volcano. The last eruption of Laki, which occurred in 1783, is considered by many scientists to be the most powerful volcanic eruption in the last thousand years.

Together with Lucky, more than 200 years ago, an entire volcanic system, led by the Gremsvotn volcano, awoke. The eruption of Laki began on June 8, 1783 with the opening of a fissure containing 130 craters.

Scientists believe that in eight months a fantastic amount of lava (14 cubic km) came to the surface, which flooded almost 300 square meters. km of the island. The eruption continued until February 7, 1784. True, the bulk of the lava erupted in the first five months.

8 million tons of hydrogen fluoride and 120 million tons of sulfur dioxide, i.e. About three times more than the entire European industry emitted into the atmosphere in 2006, killing half of Iceland's livestock. About 80% of the sheep, 50% of the cattle and half of the horses died on the island then. The famine caused by this death and the same poisonous gases claimed the lives of more than 9 thousand Icelanders, i.e. every fourth inhabitant of the island.

Other European countries were also severely affected by the Laki eruption. The summer of 1783 was unusually hot, and a rare high pressure area over Iceland caused winds to blow from northwest to southeast. Within days of the eruption, a toxic fog covered most of Europe. Of course, there were no planes then, but the ships could not go to sea due to poor visibility. Even the sun turned blood red.

Tens of thousands of Europeans became victims of the Laki eruption in 1783 and in the winter of 1784. In Britain alone, and in August and September 1783 alone, up to 23 thousand people died from poisonous volcanic gases brought from Iceland.

The sultry summer gave way to an early and harsh winter. Due to cold weather in 1784, another 8 thousand people died in Britain.

The disaster did not end there. In the spring of 1784, a very severe flood occurred in Germany and Central Europe.

The effect of the Laki eruption on the climate in the Old World was felt for several more years, causing shortages and famine everywhere.

The eruption of Laki was felt even on the other side of the Atlantic. In New England (North America), for example, there have never been such prolonged frosts as in 1783-1784; and New Jersey experienced a record amount of snow during the winter of 1784. It is said that that winter the Mississippi froze in New Orleans and the Gulf of Mexico was frozen over.

There is evidence that Laki's eruption weakened the monsoons in India and Africa and caused famine in Japan.

Nobody knows what awaits the Icelanders and the whole of Europe this time.

Zakhar RADOV