You're smarter for 10; Holidaymakers were on a tenterhooks this time last year as they waited to see whether ash from the Icelandic volcano would disrupt their plans. Reporter SARAH SCOTT looks back on the impact of the eruption.
So what actually happened this time last year? On May 22 last year, Iceland closed its main international airport and cancelled domestic flights after its most active volcano, Grimsvotn, began erupting. It was the volcano's largest eruption in 100 years and it spewed a 20km-high plume of soot, smoke and steam into the atmosphere.
Is there any volcano in particular which could erupt? It is not a case that every eruption of volcanoes in Iceland will have a similar impact on the airline industry. Prof Foulger said: "It is difficult to put your finger on when a volcano will go off. "Grimsvotn is a very active volcano, it is going to pop again and we have to get used to that."
But why were holidaymakers concerned about something happening in Iceland? It was a case of deja-vu for some as in April 2010, ash clouds from another Icelandic volcano, Eyjafjallajokul, led to the closure of a large section of European airspace causing flight cancellations. Many people became stranded in foreign countries while others missed their holidays.
So what is the likelihood of this happening again? It is difficult for experts to predict similar situations to April 2010 and May 2011. Professor Gillian Foulger from Durham University, who set up a research station on Grimsvotn in Iceland in 1996, said systems needed to be put in place to deal with these natural occurrences.
So did the ash plume of last May have the same impact as the one in April 2010? In short, no. The impact was nowhere near as severe as in 2010. There were concerns, and passengers were warned there could be delays and possible cancellations, however this eruption was to cause considerably less disruption for travellers.
But this is a natural activity which cannot be stopped, what else are they doing to minimise future disruption? The CAA say they are working the aviation industry to develop solutions that will increase flying when they are sure it is safe to do so to ensure interruption is kept to a minimum.
But if this was the biggest eruption of Grimsvotn in 100 years, why was the impact on the aviation industry not as severe as in 2010? Experts in Iceland said at the time that the eruption should not cause widespread disruption to air traffic. They said this was because, despite this eruption being much bigger.
But how does an ash cloud affect flights? It was feared that ash particles could cause aircraft engines to fail, and although the closures caused chaos to air travellers, the authorities did not want to risk allowing flights to take off. About 10 million travellers were affected and some said the shutdown was an over-reaction. So what exactly happened in April 2010 as people were so worried about a repeat situation? To travellers, it seemed like everything stopped. The April 2010 eruption of Eyjafjallajokull, caused unpredicted disruptions to flights across Europe closing the majority of airports and bringing the aviation industry to a stand-still. So we have had two brushes with ash clouds in two years, what measures have been taken to minimise disruption if this happens again? The Civil Aviation Authority (CAA) has carried out rigorous work since the 2010 crisis and are confident arrangements put in place since then will ensure the public are safe.