In late 1808, a colossal volcanic eruption disrupted weather around the world. It was one of the three biggest eruptions of the 19th century – but we don’t know where it happened.
“Colossal” is not just hyperbole – that’s the official description according to the Volcanic Explosivity Index. This mystery volcano is thought to have been roughly equivalent to Krakatoa or Pinatubo, and it would have dropped global temperatures significantly.
We know that a volcano erupted somewhere from contemporary accounts of giant cloud banks shrouding the sun, and secondary measures like sulfate concentrations in Greenland ice cores. The cloud must have been enormous: those contemporary accounts were from Lima and Bogotá, 2600km apart.
But which volcano was it? We still don’t know. The best hypotheses put it somewhere between Indonesia and Tonga – although Mount Putana in the Andes may also be a candidate, as is the Toghavitu Eruption of Savo Island.