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
2010 eruptions of Eyjafjallajökull
2010 eruptions of Eyjafjallajökull
2011 eruption of Grímsvötn