Grains of ash are dropping from the sky after a piercing detonation; they tinkle on my rucksack. Several large lava bombs blaze high above the crater, but fall back into the bowl-shaped depression, whose inner walls are striped with bands of cinders and rubble. At the bottom are two pits - one exhales a dusty smoke, but sometimes a much thicker brown cloud billows out silently to unfurl then dissipate across the larger, magma-filled vent, whose fumes are blue-tinged. Trade winds sweep ash off the outer crater rim behind me like sand off a dune, showering the grey plain below, which stretches to a tract of lime- and emerald-green scrub and bush. The humid climate does a good job of confining the volcano''s flagrant footprint. Ahead, beyond the crater, the South Pacific spans half the horizon, from silver under the sun to hazy blue. Another deafening volley! I sense the heat on my face this time as lava dances up from the sloshing maw with a roar like the full thrust of jet engines - I feel it in my chest and through my feet. The crater fills with a wreath of sulphurous fumes; they spill out, making acid tears in my eyes.

More ash prickles my skin. The experience is dynamic, elemental, mesmerising; it assails all the senses at once. Now the fumes have thickened and I can no longer see where the bombs are flying. I turn off the spectrometer I''ve been using to measure gas emissions, and start heading back to my lodge in the forest. It''s better to not sacrifice oneself for one''s art. Volcanoes get a bad press. They are most in the public eye when tourists have been assailed by lava projectiles, neighbourhoods buried beneath pyroclastic flows, populous shorelines ravaged by tsunamis, or planes grounded owing to the ash forecast. But volcanoes mean more than menace and calamity.

Dramatic and traumatic as their outbursts can be, most volcanoes, most of the time, are tranquil mountains with diverse microclimates and habitats, and valuable mineral and geothermal resources. If we think of the places where humans have long lived in the shadows of volcanoes, the volcanoes were almost invariably there first. Like our parents, they''ve led whole lives before we get to know them. They are visual anchors in our landscapes and paint the sky with their plumage; they are supernatural realms; and they can turn the world''s weather on its head. Even when their wild days are long past and their flames forever extinguished, their eroded landforms still enliven our skylines and invite outdoor adventure. Wherever we live on the planet, they are more a part of our lives than most people realise. Volcanoes loom at a thrilling crossroads of nature, spirit, climate, geology, technology, society and culture. They play with time - stretching it over a geological epoch, yet able to shapeshift and change everything in the blink of an eye.

As portals, they allow us to trace story and memory through deep time and back again. As a volcanologist, I have dedicated my career to observing simmering craters, often at very close quarters, with a view to revealing their secrets. I''ve followed in the footsteps of pioneers like the American geologist, Thomas Jaggar, who established the Hawaiian Volcano Observatory in 1912. I love his description of geology being the ''science of the dreamland of the earth''s interior'', and much of my work has involved recording phenomena at the mouths of volcanoes to help us understand their anatomy and physiology, to visualise their unseen lungs and alimentary tracts. The truth is, I spend a lot of my time imagining the underworld, and comparing the quirks and frolics of different volcanoes. They never asked for an advocate but I am not alone in seeking to translate the language of these sonorous mountains for a wider audience. Volcanoes are hard to ignore, especially if you live near one. We have probably admired and feared them ever since our species evolved in the shadows of Kilimanjaro and other fi re mountains of eastern Africa, a few hundred thousand years ago.

Given their sonic and visual spectacle, even between eruptions, it seems certain the ancestors would have sought to interpret their omens. But when did the more systematic study of volcanoes begin? Whose shoulders have I stood on in hope of seeing further? Historians of science might well diff er on its origins, but I trace volcanology''s first whispers back to the period when the term volcano was coined, and to the man whose careful observations would establish a template for centuries of colonial exploration (and exploitation): Gonzalo Fernández de Oviedo y Valdés.