Ice Cores Reveal Huge Volcanic Eruptions, Bigger Than Anything in The Last 2,500 Years

There are signs of thousands of volcanic eruptions across 60,000 years of history, with 25 of the eruptions larger than anything Earth has seen in the last 2,500 years.

There were over a thousand eruptions found in the cores near the poles. Evidence was left at both poles by a total of 85 eruptions.

There are deposits of sulfuric acid left behind by the eruptions. It gives researchers clues as to how large the volcanoes have been.

The ice corer is being examined by Anders Svensson. (NEEM)

Ice cores offer a few advantages over other methods for reconstructing ancient volcanic eruptions, according to a physicist from the University of Copenhagen.

When a really large eruption occurs, sulfuric acid is ejected into the upper atmosphere, which is then distributed globally. The amount of sulfuric acid that has fallen can be used to estimate the size of an eruption.

The team found 69 volcanic eruptions that exceeded the 1815 Tambora eruption, which was enough to block out sunlight, using the Volcanic Explosivity Index (VEI), which ranges from a low of 1 to a high of 8.

There were two eruptions in Toba, Indonesia, around 74,000 years ago, and one in Lake Taupo, New Zealand, some 26,500 years ago. In comparison, the Eyjafjallaj kull eruption in Iceland scored 4 on the VEI scale, while the 2012 Puyehue-Cordón Caulle eruption in Chile scored 5.

We might not have much of a wait until the next one because VEI 7 eruptions happen once or twice every thousand years. According to the researchers, the next VEI 8 eruption could be in a hundred years or a few thousand years.

The eruptions in the ice cores would have been much larger and more catastrophic than the ones in living memory. The research fills in some of the blanks in Earth's volcanic record, a record that before now has been a bit fuzzy.

The new 60,000-year timeline of volcanic eruptions provides us with better statistics than ever before, says Svensson.

We can see that there were more great eruptions during the prehistoric Ice Age than in modern times. Large eruptions are relatively rare, so a long timeline is needed to know when they occur. That is what we have now.

The researchers were able to more accurately identify the eruptions that had significant effects in both Antarctica and Greenland by using previous work.

The research is more than just a lesson. Ice cores give us a window into the effect of eruptions on the global climate. The biggest events can cause cooling for a long time.

Knowing how sensitive the Earth's climate is to major events like those documented in the ice cores can inform future climate models.

Ice cores contain information about temperatures before and after the eruptions, which allows us to calculate the effect on climate.

The research has been published.