No-one alive today has witnessed a volcanic eruption remotely as big as the Toba “super” eruption. This mega-colossal eruption was the third – and largest – in the last million years at Toba, and the most explosive on Earth for more than two million years. More than seven trillion tonnes of volcanic material were ejected, of which at least 800km3 was spewed as ash across the Indian Ocean and the adjacent landmasses of South and Southeast Asia, covering several million square kilometres of the planet’s surface in debris.
The Toba blast pumped an equally staggering quantity of sulphurous gases into the atmosphere. The resulting chemical products were transported around the globe and are recognised as sulphate spikes in drill cores collected from ice sheets in Greenland and Antarctica.
The event dwarfs any other historical eruption, the largest of which was Tambora – also in Indonesia – in 1815. Despite being 100-times smaller in magnitude than Toba, Tambora led to a global drop in temperature of about 0.7 ºC and disastrous crop failures across the Northern Hemisphere the following year – dubbed “the year without a summer”.
Via Catherine Russell