The world has been severely impacted by the March 2010 eruption of glacial volcano Eyjafjallakokull. Flights coming in and out of Europe were halted for one week due to drifting volcanic ash and dust that made for potentially dangerous flying conditions. Recently most flights have been resumed, but the threat of an eruption still exists, and attention has been diverted to Katla, a neighboring volcano with a repeated history of even more violent eruptions.
Katla peaks at 1512 meters and is located east of the smaller glacier Eyjafjallajokull. It is also partially covered by the Myrdalsjokull glacier with an area of 595 km². The major concern for geophysicists is that the recent eruption will trigger an even more powerful eruption of Katla, which has been the historical trend. Eyjafjallojokull has blown 3 times in the past thousand years, in 920AD, in 1616, and between 1821 and 1823. Each time it set off Katla.
The volcano normally erupts every 40-80 years and its last eruption was in 1918, shown in the photograph above, which was sold at an auction to Bjornsog Toggle. Following the 2010 eruption Icelandic President Olafur Grimsson released a statement "the time for Katla to erupt is coming close... we [Iceland] have prepared... it is high time for European governments and airline authorities all over the world to start planning for the eventual Katla eruption".
Eruptions like this put our small world into perspective. One volcano erupts and it can have an enormous impact on the rest of the world. For example, consider Iceland's worst modern time eruption in 1783 when the Laki volcano blew. The lava shot 1.4 km into the air and more than 120 million tonnes of sulphur dioxide was released into the atmosphere, which would transform the world. The results included Britain's notorious "sand summer", creating havoc with harvests in France, and changing the climate so dramatically that New Jersey recorded its largest snowfall and Egypt experienced one of its most enduring droughts. For now we can only wait and hope for the best...