Scary! Except that according to the article itself:
- Scientists don’t actually know whether the volcano, Bárdarbunga, will erupt, just that there has been an increase in earthquakes near it.
- There are very few measuring devices in the area, which means seismologists don’t know whether those earthquakes are actually caused by the volcano or not.
- No-one, apart from the Mail itself, is claiming that the eruption will be larger than Eyjafjallajökull, and they seem to be basing that solely on the fact that the volcano itself is bigger.
In conclusion, a volcano may or may not erupt, and it could or could not be bigger than another volcano. Things are always less terrifying when you know the uncertainties.
Edit: Sure enough, the scientist studying Bárdarbunga has said on Radio Five that his findings have been misquoted and exaggerated by the media and other Icelandic geologists agree that the danger has been overstated. What a surprise.
Double edit: Massive thanks to Alex Elliott in the comments for finding this article where the professor in question, Pall Einarsson, attacks the press for twisting his words and overhyping the scare. In the original interview, he claims to have said the exact opposite – that the earthquakes around Bárdarbunga were nothing unusual.