Will Krakatoa rock the world again?

Bright orange lava spews up into the air, dark smoke mingles with the clouds and the gloomy night takes on an ominous red glow. Towering 1,200ft above the tropical stillness of the Sunda Strait in Indonesia, one of the most terrifying volcanoes the world has ever known has begun to stir once more. Almost 126 years to the day since Krakatoa first showed signs of an imminent eruption, stunning pictures released this week prove that the remnant of this once-enormous volcano is bubbling, boiling and brimming over. With an explosive force 13,000 times the power of the atomic bomb that annihilated Hiroshima, the 1883 eruption of Krakatoa killed more than 36,000 people and radically altered global weather and temperatures for years afterwards.

The eruption was so violent and catastrophic that no active volcano in modern times has come close to rivalling it, not even the spectacular eruption of Mount St Helens in the U.S. in 1980. Now, almost a century-and-a-half on, are we about to experience the horrors of Krakatoa once again? 'Volcanic prediction is getting better,' says Professor Jon Davidson, chair of Earth Science at Durham University and a volcanologist who has studied Krakatoa first-hand. 'But we are never going to be able to fully predict big and unusual eruptions, precisely because they are unusual.' Yet there is little doubt that if Krakatoa were to erupt again with such force and fury, the impact would be far more devastating than that which was experienced in the 19th century.

Official records of the time show that the 1883 eruption, together with an enormous tsunami it generated, destroyed 165 villages and towns, seriously damaged a further 132 and killed 36,417 people outright. Nearly 150 years on, the region where Krakatoa is situated between the islands of Java and Sumatra in the Indonesian archipelago is more densely populated, with small farmers drawn to the rich and fertile volcanic soils of the area. It is not inconceivable that hundreds of thousands of people could be killed if there were another massive eruption. Krakatoa had an extraordinary effect on the planet last time round. Average global temperatures following the eruption fell by as much as 1.2 C, as the huge quantities of sulphur dioxide pumped into the atmosphere resulted in clouds that reflected a greater amount of incoming light from the sun.