How many volcanic eruptions have there been in 2010?

1

In 2010 there was one single volcanic eruption, the eruption of Eyjafjallajökull, in Iceland.  It is widely known the fact that this eruption caused enormous disruption to air travel across western and northern Europe over an initial period of six days in April 2010.  Needless to say, about 20 countries closed their airspace to commercial jet traffic and it affected more than 100,000 travelers.  The eruption started on 20 March 2010.  Moreover, the second phase of the eruption started on 14 April 2010.