Grimsvotn, one of Iceland's most active volcanos, has erupted massively causing fears of air travel disruption but at the moment that is only confined to Iceland and some limited Scandinavian atlantic routes.

Last year, ash from the volcano Eyjafjallajokull, about 150kilometeres away from the current eruption centre, caused massive European flight disruption that affected around 10 million travellers.

The ash caused by last year's eruptions was lighter and the winds were such that the ash cloud was carried deep into European airspace, causing the largest flight shut down in European skies  since World war 2.

The ash from Grimvotn is heavier so more likely to fall locally, though the initial cloud reached an altitude of 12 miles, currently spewing out to half this distance.

The worry is that aircraft will damage their engines by flying through the ash cloud but for now this probability is quite localised,  though the eruption is the largest from this volcano for a hundred years