Ash fall-out through the ages

New Scientist’s rather timely cover story this week looks at the eruption of supervolcano Toba, 74,000 years ago and the impact and scale of ash fall-out from it. As New Scientist explains: Toba is a supervolcano on the Indonesian island of Sumatra. It has blown its top many times but this eruption, 74,000 years ago, […]