Iceland’s volcanic activity went into overdrive recently over a series of earthquakes. This was very worrying and it was feared that the biggest volcano here was going to erupt.
In 2011 the Icelandic volcano Eyjafjallajokul brought Europe to a standstill. The volcano’s eruption went on for over a month and released a voluminous column of ash several kilometres high, which was circulated by the jet stream. This led to the closure of European Air Space and shut down air traffic for six days leading to economic loss and severe delays for travellers. Katla is Iceland’s biggest volcano and can produce a much bigger eruption and cause disruption. If this were to erupt we would experience a catastrophe similar to that of the 1991 Mount Pinatubo eruption.
Katla’s geological position in Iceland gives the country the identity as the land of fire and ice. Iceland’s volcanos are special because some of them are covered in layers of snow and ice. These are known as subglacial volcanoes. Katla is 4961 feet tall, partially covered with a massive glacier. The last time it erupted in 1918 it released a massive amount of steam, caused by the hot lava melting the glacier above it. This caused a massive amount of meltwater to travel across the area carrying icebergs in it’s path.
Katla’s eruption also managed to craft the landscape of Iceland by extending the south coast by 5 kilometres. It did this by using laharic flood deposits, a mudflow that consists of a slurry of pyroclastic material and water. It didn’t cause much damage locally and there were casualties but the effect on the climate that followed would lead to devastation that reached far from Iceland. The sky was pitch black over the country for the next few days and the surrounding landscape was blighted. Some farmers had to abandon their livestock to the floods.
But if that eruption was bad then imagine what impact Katla could have today. If Eyjafjallajokul caused travel chaos then Katla could cause a climatic event. Volcanic eruptions are measured by their Volcanic Explosivity Index (VEI). Katla’s past eruptions have a VEI of 4 – 6. The most recent example of an eruption like this is the 1991 Mount Pinatubo eruption in the Philippines.
Supervolcanoes like Katla and Pinatubo can have a climatic effect both locally and worldwide. Reykjavik is only 27 kilometres west from Katla. Although Iceland is prepared to deal with volcanic activity Katla’s impact on the whole of Iceland will be huge. With a VEI of 6 Katla can explosively release over 10 billion tonnes of material and an eruption column over 25 kilometres high. That would be enough to cover the whole of Iceland and as the events of Pinatubo have show the local vegetation could be wiped out. With a glacier sitting on top of the vent it also lead to large parts of Iceland being flooded.
As for the effect on the climate the ashes would circulate in the same way as it did in 2010. But that is only part of the impending danger. The eruption column can create a massive black grey cloud that can bring darkness to wherever it’s carried by the wind. That ash can also cause a global fall in temperatures. When particulates of volcanic ash get carries through the air they can block out the Sun and reduce the heat reaching the surface. Volcanologists estimate that there will be a worldwide temperature drop of 2 degrees centigrade, should Katla erupt.
There’s also potential disruption to agriculture just like what happened around Pinatubo in 1991 when £ 22.5 million of agriculture was devastated. If such a catastrophe were to hit Europe there would probably be an adverse effect on the farming industry in Europe.