LONDON – A volcanic eruption that unleashed a global torrent of acid rain wiped life from the oceans 260 million years ago, scientists have discovered.
The eruption, in Emeishan Province, southwest China, disgorged half a million cubic kilometres of lava covering an area five times the size of Wales.
Unusually, scientists were able to pinpoint the exact timing of the event and found that it coincided with a global mass extinction of marine life.
The eruption occurred in a shallow sea, with the collision of hot fast-flowing lava and sea water setting off a violent explosion. Scientists compared the reaction to “throwing water into a chip pan”.
Huge quantities of sulphur dioxide would have been thrown high into the atmosphere, generating a blanket of cloud that cooled the planet and caused a downpour of acid rain.
Prof Paul Wignall, from the University of Leeds, who led the research, said: “The abrupt extinctions of marine life we can clearly see in the fossil record firmly link giant volcanic eruptions with global environmental catastrophe, a correlation that has often been controversial.” The findings were published yesterday in Science.
Previous studies have linked increased levels of carbon dioxide from volcanic eruptions with mass extinctions. However, because of the long-term warming effect of the greenhouse gas, the causal link between volcanic eruptions and global environmental changes has not been clear. – (PA)