Art by Basil Wolverton
Changes to the Earth's oceans, caused by extreme volcanic activity, triggered the greatest extinction of all time 252 million years ago that wiped out more than 90 per cent of marine species and more than two-thirds of the animals living on land.Abstract: Ocean acidification triggered by Siberian Trap volcanism was a possible kill mechanism for the Permo-Triassic Boundary mass extinction, but direct evidence for an acidification event is lacking.
In the latest Permian, increased ocean alkalinity primed the Earth system with a low level of atmospheric CO2 and a high ocean buffering capacity. The first phase of extinction was coincident with a slow injection of carbon into the atmosphere, and ocean pH remained stable. During the second extinction pulse, however, a rapid and large injection of carbon caused an abrupt acidification event that drove the preferential loss of heavily calcified marine biota. PR