Ian Barnett on Iceland’s volcanic past and future
Iceland has long been known as the land of fire and ice; precariously bridging two tectonic plates, it has a fierce volcanic history. For thousands of years, the landscape has been transformed by the power of lava, with each eruption creating or destroying a part of the landscape in a matter of minutes. New islands have even appeared, with the emergence of Iceland’s most southerly island, Surtsey in 1963. In 1783, a quarter of the country’s population was wiped out when the Laki fissure opened, releasing poisonous hydrogen fluoride gas and covering much of Europe in a noxious fog. The haze released caused extreme climate changes, from heavy snowfall in New Jersey to severe drought in Egypt. Over the past two years however, more than just the local residents have started to fear Iceland’s next eruption.
In April 2010, the eloquently named Eyjafjallajökull volcano erupted, releasing a 9 kilometre high ash plume, which blew as a cloud over Europe and down the coast of Canada. The ash particles were small and harmful to aircraft engines, leading to strict no fly zones, bringing many European airports to a standstill. This volcanic event was considered minor compared to many past eruptions on the island, yet cost the aviation industry over $2 billion due to lack of preparation. This kept everything from plush private planes to Ryanair firmly on the ground in the UK for 5 days.
Grímsvötn, one of Europe’s most active volcanoes and responsible for the aforementioned Laki eruption, started erupting just over a year later in May 2011. The ash released from this eruption however was composed of larger particles than that of the previous Eyjafjallajökull eruption, and hence was not suspended in the air for so long. This meant that only airspace in northern Europe was briefly closed, and cancellations were much less widespread than in the preceding year.
Katla is Eyjafjallajökull’s big brother, they are located only 25 kilometres apart. Named after an evil troll, this volcano is positioned in southern Iceland and stands at 1512 metres, under permanent ice. Historically, Katla has erupted on average every 50 years, with the last eruption on 12th October 1918, meaning an eruption is long overdue. Over the last 400 years, eruptions have lasted anywhere between 13 and 120 days. According to scientists studying the area, a series of recent earthquakes make an eruption in the near future increasingly likely.
If Katla were to erupt, not only would the ash cloud produced hinder aviation in the area, widespread flooding would occur. When the lava comes into contact with the Mýrdalsjökull glacier, under which Katla sits, a flash flood, or jökulhlaup as they are known locally, would wash away anything in its path. After the last eruption, the coastline of southern Iceland was extended by five kilometres. Combined with an ash cloud that could block out the sun and the release of poisonous gases from the volcano, hard times may hit the locals, with loss of crops and livestock affecting the local agriculture industry. Generally when large volcanoes erupt, the Earth’s ecosystem is vastly affected, the ozone layer thins and temperatures fall. The incidence of skin and eye irritation increases and the jagged ash particles can cause lung irritation. However, sulfur aerosols released into the atmosphere can reduce global warming, when dissolved in water to form sulfuric acid. These particles absorb and scatter radiation from the sun, preventing it reaching Earth.
History states that Katla has a tendency to erupt within months of Eyjafjallajökull, but are we safe 18 months on from the last eruption? The strongest earthquake in the region recently measured 4.1 on the Richter Scale, and of course Icelandic authorities have evacuation plans in place, but with the last eruption being some 93 years ago, does anyone really know what to expect? Katla’s magma chamber is ten times larger than Eyjafjallajökull’s, so frequent fliers beware; when Katla erupts, and it is a matter of when rather than if, you’ll know about it!
Image credit –Joschenbacher