Volcanoes are the most violent surface expression of the Earth’s internal energy. Only impacts of large extra-terrestrial bodies can match the explosive release and devastation of the largest volcanoes. Indeed for some of the most dramatic events the Earth has seen - the large terrestrial extinctions of animal life - the jury is still out as to whether they were brought about by meteoritic impact or by wide-scale effects of volcanic activity. Volcanoes have it too when it comes to sustained visual impact. Earthquakes, tsunamis and avalanches all cause massive devastation, but it is accomplished in the blink of an eye, and floods rise with a progressive and depressing inevitability. Volcanoes are simply the most spectacular of the destructive natural hazards to life on Earth.

To those who are far enough away to view them in safety, volcanoes can offer a truly awe-inspiring pyrotechnic display of the Earth’s innate power- a natural, spectacular son et lumière. For this reason from time immemorial they have exerted a siren-like attraction for geologists, photographers, filmmakers and many others. And, like the sirens of ancient fable, they have lured to their death all too many of those who dared to get too close. Indeed volcanoes inspired such awe in the ancient world that their own mythology sprang up about them. Cyclops, the one-eyed giant who all-unprovoked threw rocks great distances to kill shepherds tending their flocks, we know today as Mount Etna. The giant was also able to cause springs to flow where he struck the ground-it is not uncommon for groundwater flows to be disrupted during volcanic episodes.