2010 eruptions of Eyjafjallajökull were volcanic events at Eyjafjöll in Iceland which, although relatively small for volcanic eruptions, caused enormous disruption to air travel across western and northern Europe over an initial period of six days in April 2010. Additional localised disruption continued into May 2010. The eruption was declared officially over in October 2010, when snow on the glacier did not melt. 14–20 April ash covered large areas of northern Europe when volcano erupted. About 20 countries closed their airspace (a condition known as ATC Zero) and it affected hundreds of thousands of travellers. The European flights avoided about 344,109 tonnes of CO2 emissions per day, while the volcano emitted about 150 000 tonnes of CO2 per day.
Seismic activity started at the end of 2009 and gradually increased in intensity until on 20 March 2010, a small eruption started rated as a 1 on the Volcanic Explosivity Index.
Beginning on 14 April 2010, the eruption entered a second phase and created an ash cloud that led to the closure of most of Europe's IFR airspace from 15 until 20 April 2010. Consequently, a very high proportion of flights within, to, and from Europe were cancelled, creating the highest level of air travel disruption since the Second World War.
The second phase of the eruption started on 14 April 2010 and resulted in an estimated 250 million cubic metres (330,000,000 cu yd) (¼ km3) of ejected tephra. The ash plume rose to a height of approximately 9 kilometres (30,000 ft), which rates the explosive power of the eruption as a 4 on the Volcanic Explosivity Index.
By 21 May 2010, the second eruption phase had subsided to the point that no further lava or ash was being produced.
By the morning of 24 May 2010, the view from the web camera installed on Þórólfsfell showed only a plume of water vapour surrounded by a blueish haze caused by the emission of sulphurous gases.
Due to the large quantities of dry volcanic ash lying on the ground, surface winds frequently lifted up an "ash mist" that significantly reduced visibility and made web camera observation of the volcano impossible.
By the evening of 6 June 2010, a small, new crater had opened up on the west side of the main crater from which explosive activity was observed with the emission of small quantities of ash. Seismic data showed that the frequency and intensity of earth tremors still exceeded the levels observed before the eruption, therefore scientists at the Icelandic Meteorological Office (IMO) and the Institute of Earth Sciences, University of Iceland (IES) continued to monitor the volcano.
In October 2010, Ármann Höskuldsson, a scientist at the University of Iceland Institute of Earth Sciences stated that the eruption is officially over, although the area is still geothermally active and might erupt again.
In May 2011, a nearby volcano named Grímsvötn started erupting, causing similar air travel disruption.
Source : Wikipedia
