Humans 'thrived' after historic Mount Toba eruption

From BBC - March 13, 2018

Early humans may have flourished after the largest volcanic eruption in history, according to new research.

Mount Toba erupted in Indonesia about 74,000 years ago.

The event was long thought to have caused a volcanic winter, drastically reducing the global human population at the time.

Recent excavations in South Africa suggest that settlements there not only endured the cataclysm, but may have "thrived" in its wake.

The findings complement previous work in Lake Malawi, which searched lake bed cores for evidence of a global climate catastrophe at the time of the eruption, but could find none.

Looking through time

An international team excavated two sites on the south coast of South Africa, finding evidence of human activity both before and after the eruption.

"We are the first ones to really address the question of the Toba hypothesis in Africa. It's in Africa that it really counts, because that's the source location of modern humans," Dr Marean, an author of the paper published yesterday in Nature, told BBC News.

The scientists found tiny shards of volcanic glass in the sediment at both sites. These form part of the debris ejected from a volcano during an eruption, known as tephra.

When chemically analysed, the shards were found to be a match for Mount Toba, around 9,000 km away. These are thought to be the first volcanic deposits of their kind recorded so far from their source; further testament to the strength of the Toba eruption.

It is believed to have been the largest on Earth in the last 2.5 million years

Due to lava's distinctive composition, it can be dated using a radioisotope technique called argon-argon dating. This has allowed volcanologists to calculate a fairly narrow window for Toba's eruption.

A new hope


Continue reading at BBC »