Humans flourished during volcanic winter, study says

After the most devastating supervolcano eruption in the past 2.5 million years, an enclave of humans flourished in the ensuing volcanic winter, a new study has found.

The Toba supervolcano on present-day Indonesia threw out 3000 cubic kilometres of rock, ash and dust about 74,000 years ago.

The explosive event blocked the Sun with ejected dust and particles, causing massive climate disruption.

Many scientists believed widespread famine and sharp population dips followed – even pushing some species - including humans - to the brink of extinction.

But now a study by an international team of researchers - published in Nature - shows a small group of humans not only survived the devastation but flourished.

The scientists – including the University of Wollongong’s Professor Zenobia Jacobs – studied two archaeological sites on the South African coast ­where humans lived at the time of the Toba eruption.

Their painstaking work revealed microscopic glass shards - known as cryptotephra -  were spewed out by Toba in sediment layers at the sites.

It was the first time the shards had been found outside the supervolvanco – 9000km away.

But the scientists also uncovered evidence of flourishing human activity at the two South African sites – hundreds of stone stools, bones and evidence of human fire building.

“I think this study shows the effect of the Toba eruption wasn’t so destructive as previously thought,” Prof Jacobs told nine.com.au.

“Maybe the results on the human population weren’t so dramatic.”

And it appears the coastal location of this human enclave played a major factor in their survival.

Shellfish and fish were not so affected by the climate change as plants and fauna, and offered a reliable food supply.

"Shellfish in particular aren't as affected by changes in climate as with terrestrial flora and fauna. It's a reliable resource," Prof Jacobs said.

"But if you're in the middle of the country, and there's extinction or change in flora and fauna, it might be more difficult to find enough food sources, or you have to adapt all the time."