Volcanic past

Ice cores collected from Antarctica and Greenland have revealed gigantic volcanic eruptions from the last ice age that were much greater than any that have taken place in modern history. Until now, it has been difficult to determine the number and size of volcanic eruptions that happened more than 2,500 years ago, but by analysing and dating sulphur deposits in the cores, researchers at the University of Copenhagen have been able to estimate a timeline of intense volcanic activity over the past 600,000 years, including 69 eruptions larger than that of Mount Tambora in 1815, which was so huge it caused average global temperatures to decrease by half a degree Celsius.