The danger is that the small volcano is just the beginning and that it will trigger the far more powerful volcano of Katla, which nestles beneath Myrdalsjoekull.
"Eyjafjallajokull has blown three times in the past thousand years," Dr. McGarvie told The Times, "in 920AD, in 1612 and between 1821 and 1823. Each time it set off Katla." The likelihood of Katla blowing could become clear "in a few weeks or a few months", he said. -- Times Online