About 74 thousand years ago on the island of Sumatra there was a terrible eruption of Toba. According to estimates, it was 5 thousand times bigger eruption of mount St. Helens in 1980. Yes, there is a major eruption on the planet for the last 2 million years!

The crater of the volcano Toba (image William Bowen, California Geographical Survey).

Toba vomited so much of lava that would be enough for the two of mount Everest. Huge clouds of ash covered the sun for many long years. The explosion left a crater with a diameter of 50 km addition Anders Svensson from the University of Copenhagen (Denmark) and his colleagues found that both poles rained of sulfuric acid.

Scientists have calculated what the depth of the ice caps of Greenland and Antarctica should look for traces of eruption of Toba, but still could not find any residue ash. But this time found layers of sulfuric acid. Dating converges.

Analysis of core samples were also clarify the details of how radically changed the climate in the years after the eruption. Previously, researchers have estimated that such an event could lead to a decrease in average global temperature of 10 C and that cold could last decades. In fact, judging by the cores cooling was short and not had a global character. The southern hemisphere is practically not noticed.

In addition, new data could settle some archaeological debates. The Toba eruption occurred at a critical moment in the early history of mankind, when Homo sapiens first poked his nose out of Africa. Scientists would like to know, did the story of our family this event and can you talk about destruction of a significant part of the population.

Layers of ash found in Asia, are a very important starting point for working with the artifacts that are too old for radiocarbon Dating. Detection of acid layers in the ice cores may become another background, which will place the archaeological finds in the climate context.

The study is published in the journal Climate of the Past.

Prepared according to LiveScience.