Scientists have learned where the most powerful volcanic eruption of the modern geological era took place. The total volume of the explosion was between 332 and 427 cubic kilometers. Volcanic eruptions are vital to both the planet’s geology and biology. They can affect the climate, that is, people. Scientists are still debating the significance of the eruption of the Toba volcano on the island of Sumatra 75,000 years ago, which spewed volcanic ash about 800 kilometers into the air.

There is an opinion that this event affected the climate of the entire planet and even led to the so-called bottleneck effect in our ancestors – an impoverishment of the gene pool due to a very sharp decrease in the population (to several thousand, to hundreds, or even to several thousand). dozens of individuals and sometimes units). Indeed, there was a point in our evolutionary history when the African Homo population, once numbering about 100,000, decreased by a factor of 10 (although some studies reject this fact). However, there are studies that show that the volcanic winter did not reach Africa and that our ancestors were innocent in its destruction.

In any case, the study of past volcanic eruptions is an important task in understanding our own history and the history of the Earth’s biota in general. It may also be useful in predicting the consequences of future eruptions.

Researchers from Kobe University (Japan) examined the 19-kilometer-diameter Kikai caldera, flooded by the ocean, located near the Osumi Islands in Japan’s Kagoshima Prefecture. The study was published on: Journal of Volcanology and Geothermal Research.

The scientists conducted a seismic survey and also took samples of bottom sediments around the caldera. This allowed them to get a very detailed picture of what was going on in these regions thousands of years ago.

And all this is due to the fact that volcanic emissions accumulated in the sea are much better preserved than on land, in the latter case they are destroyed under the influence of erosion. In this way, scientists carried out a comprehensive stratigraphic analysis of seismic activity data around the caldera, dividing the surface layers over 100 meters thick into five blocks. This is how researchers learned that the sediments on the ocean floor and nearby islands have the same origin.

After analyzing the samples, scientists concluded that 7,300 years ago the local volcano ejected into the environment between 332 and 427 cubic kilometers of eruption products, which settled in an area of ​​​​more than 4,500 square kilometers around the epicenter. All this was accompanied by the collapse of the underwater caldera. Scientists believe this event may have been the largest volcanic eruption to occur during the Holocene, the modern geological period that followed the Pleistocene about 11,700 years ago.