Eyjafjallajökull

It was April 17, 2010, and Iceland's Eyjafjallajokull had just erupted, sending out great big ash clouds that were causing widespread air traffic disruption in parts of Europe.

Almost 640 flights were cancelled in Germany on Jan. 10 as security staff went on strike at three airports, meaning disruption for around 100,000 passengers.

An earthquake struck the region around Iceland's Bardarbunga volcano on Sept. 7 while fissures in the area continued to spew out lava but still none of the ash that could hamper airline traffic.
   

A possible eruption of Iceland's biggest glacier, the Vattnajokull, is unlikely to prompt severe traffic disruptions, a EU source has explained.

Vattnajokull is also the country's second-highest peak.

The source, however, has added that air traffic might be disrupted as some EU member states might take the step.