Mount Tambora
The Indonesian volcano behind the 1816 Year Without a Summer
The deadliest volcanic eruption in recorded history did not happen at Vesuvius or Krakatoa but at a mountain few in the West could name. In April 1815, Mount Tambora on the Indonesian island of Sumbawa exploded with a force that dwarfed every other eruption of the past several centuries, killing tens of thousands directly and, through its lingering veil of ash, plunging the entire globe into a year of failed harvests and famine the following summer. It was a catastrophe whose effects reached from Indonesian villages to New England farms and European wheat fields.
Before 1815, Tambora stood perhaps 4,300 metres tall, but the eruption decapitated it, leaving a peak of about 2,851 metres rimmed by a caldera six kilometres across. Sitting on the Sunda volcanic arc, it unleashed a VEI-7 eruption, the largest in over a thousand years, ejecting tens of cubic kilometres of rock and pumping enormous quantities of sulphur into the stratosphere. That aerosol haze spread worldwide, dimming the sun and dropping global temperatures by as much as a degree. The energy released was many times that of Krakatoa, yet because it predated the telegraph, the eruption never seared itself into popular memory as later disasters did.
The consequences rippled across the planet in 1816, remembered as the Year Without a Summer. Snow fell in June in New England, crops failed across the Northern Hemisphere, and food shortages drove unrest and migration. The gloomy, storm-wracked weather kept a group of writers indoors by Lake Geneva, where Mary Shelley conceived Frankenstein. On Sumbawa, an entire local culture was wiped out, its language and customs lost beneath the ash, a buried Pompeii of the tropics that archaeologists have only begun to uncover.