'Doomsday' can last hundreds of thousands of years

According to the US news network, the team of American university scientists conducted a study and found that the phenomenon of mass destruction does not necessarily happen suddenly but can take place slowly.

The team has given strong evidence that mass destruction on Earth took place in a process that took hundreds of thousands of years.

Scientists called the event about 252 million years ago at the end of the Permian "Great Era" when about 90% of all living things disappeared.

The lead researcher, geologist Thomas Algeo of the University of Cincinnati, studied chemical evidence buried in the layers of rocks that formed the Arctic region of Canada during the destruction event.

Since then, scientists have linked this event to a long and massive volcanic eruption in Siberia.

Algeo said the eruption had emitted a large amount of methane when burned through a coal mine, causing a greenhouse gas effect that seemed to have lasted tens of thousands or hundreds of thousands of years.