Iceland's ash cloud of the apocalypse

And there is one more embellishment important to sound and rhythm: the umlaut on the o. Eyjafjallajökull. That just about nails all the intricacies of this new cult name (pronounced ay-yah-FYAH-lah-yer-kuhl) that has tangled our tongues and garbled our glottals in recent weeks while it has gone on spewing ash — a new cliché for our turbulent climatic times — all through the airways, creating alarm and confusion in airports like Frankfurt, Heathrow and Charles de Gaulle, where alarm and confusion are never very far away at the best of times and don't need unprecedented and spectacular terrestrial help to speed them along.

Not actually unprecedented, as a matter of fact. A bit of research reveals that Eyjafjallajökull has a long memory and an apparently unassuageable anger that broods along through the centuries and every now and then, well, erupts, spewing etc. This happened in 920, 1612 and frequently between 1821 and 1823. In the scramble to appear informed about dramatic geological phenomena, however, few have noticed that Eyjafjallajökull has a loyal and infinitely more pronounceable follower, a partner which dutifully echoes its (her? his?) more famous and ill-tempered mate.

Twenty-five kilometres from Eyjafjallajökull is another volcano named Katla. Katla specialises in subglacial eruptions that make the explosions of its consonant-heavy neighbour sound like genteel coughing. What's more, although it seems intrusively intimate to say so, Katla has a very large magma chamber. More intimate is their relationship. Every single time Eyjafjallajökull erupted between 920 and 1823, Katla followed a short time after with a more spectacular performance, as if to insist it was no mere footnote but actually the main text.

Icelandic President Ólafur Grímsson is in no doubt about Katla. 'The time for Katla to erupt is coming close,' he said, even as Eyjafjallajökull's black scowl was spreading over Europe's skies. 'Iceland', he said, 'was ready and it was high time for European governments and airline authorities all over the world to start planning for the eventual Katla eruption.'

Many Icelandic geologists and geophysicists agree. They fear that the Eyjafjallajökull eruption could trigger Katla, precipitating huge floods, as glacial ice melts, and building prodigious aerial escarpments of ash. The disruptions of last April would look like a half-cocked rehearsal.

Volcanoes occupy a special, ill-defined place in human imagination. Fire and flood, in the argot of our time, are 'events'. They come, they pass by. And drought creeps in, settles, grinds people down, exhausting them by its unambiguous, seemingly permanent presence. But volcanoes are aloof, squatting in the landscape, inscrutable; perhaps dead, perhaps with millennial shudders of life; perhaps seething day after day, potent, imminent their action endlessly deferred. Even for those living in their shadow, volcanoes assume a deceptive familiarity: their long drawn out threats seem too much like crying wolf to interfere with daily routines. And then they explode.

Twenty-five million years ago, the eruption at Lake Toba in Sumatra deposited metre-thick carpets of ash continents away, engendered a decade of winter darkness and massively depleted the human population. It was the quintessential volcanic catastrophe. More recently, Vesuvius ruined the great work of time and humbled an empire. Only Chimborazo, Cotopaxi and Popocatepetl, trading on their euphonious names, have a benign presence in volcanic lore.

Which brings us back to Eyjafjallajökull. True to the mould, it waited an age in suppressed fury then scorched the skyways and threatened whole economies, governments and established ways of life, with strangulation. And acolyte Katla waits its hour.

Curiously, volcanoes are not much cited by people who detect chiliastic and end-of-the-world meanings in natural disasters. This may be because while it's dramatic to assemble on a hilltop to watch the stars go out forever, it's much less comfortable hanging round the drum-rolling slopes of a magma- and fire-spitting volcano waiting for apocalypse.

Another reason is that volcanoes are mysterious. Their violent, scarcely predictable messages come from the deepest of the planet's secret places, are punctuated by sometimes centuries of deceptive silence, and are difficult to interpret. Fires, floods, droughts, tsunamis, hurricanes, earthquakes are like serial correspondence from the world we live in, reminders that our inhabitation of the earth is not autonomous, not a matter of being lords of all we survey: sometimes we think we are, sometimes it seems as if we are, and sometimes, as for example in the case of climate change, we strenuously espouse denial in order to re-enforce our insistence that we are.

Volcanoes, dotting remote landscapes all over the planet, with millennia-long histories and emanating a kind of preternatural, primal, patience, are more like aloof, rarely encountered but uncomfortably persistent landlords, whose unchanging message is: you are renting; you haven't bought.