The ash content from the Grímsvötn volcano in Iceland had a much lower silica content (50%) compared to the ash from the 2010 eruptions of Eyjafjallajökull (63%), giving the latter a higher viscosity. The ash emitted from Grímsvötn is also more coarse than the smaller, more abrasive particles emitted from the Eyjafjallajökull eruption as a result of the basalt-based magma of the Grímsvötn volcano exploding through the glacier, rather than reacting with meltwater.