Why do'nt the Icelanders pump vast amounts of liquid nitrogen or liquid helium into the volcanic interior? At such extremes of temperature, the liquid nitrogen would rapidly convert to gas and absorb the thermal energy fom the molten rock or magma, undoubtly resulting in its solidification. The glacial meltwater could be harnessed and diverted into the volcanic vent, quenching the magma and producing copious amounts of water vapour. This water vapour would undoubtly condense on the surfaces of the airborne volcanic particles, flushing them out of the atmosphere. Nature can be tamed by mankind, but such a feat requires scientific ingenuity
And I must be bored, because I've replied:
Sounds like a good idea, but I don't suppose the Icelanders have that much liquid nitrogen to hand. The world can help by organising a massive airlift of liquid nitrogen (and liquid helium too, why not) to Iceland. At once!
So nice to debate with a fellow scientist!