According to new research it would have taken less than 30, 000 years to kill more than 90% of the planet’s species 252 million years ago. The greatest mass extinction in the history of our planet happened in “a blink of an eye” geological speaking.
Our planet has seen five mass extinctions. The most important happened 252 million years ago between the Permian and the Triassic period. At the end of this period, 90% of marine life and 70% of land species disappeared. When we try and understand what caused this mass extinction today, the time frame between the start and the end of the episode still remains uncertain. Some researchers believe that everything happened within 60,000 year. However a recent study has shortened this time scale.
Researchers have carried out analysis on closely spaced layers of Penglaitan sediments found in volcanic material in South China. Their researcher reveals that the majority of species during this period disappeared in less than 31,000 years. This is a very short period of time geologically speaking. Out of the the 66 species that were found in one section, 29 of them had disappeared in this time frame.
Mass extinction could have taken place in a few thousand years however problems in dating rock sediments means it is difficult to fix an exact time period. However Shu-Zhong Shen from the Chinese Academy of Sciences said that from his research “extinction is really much, much faster than ever before. It is consistent with a single volcanic event and was probably no longer than 3,000 years” although “31,000 is the upper limit of the extinction.” He is the lead author of the study published in Geological Society of America journal.
Researchers noted that sustained eruptions 420,000 years before mass extinction would have made the planet’s ecosystem more fragile. This would have gradually weakened by intense volcanic activity and methane gases being released from the seafloor. Eventually one major eruption would have been the final blow for all living species.
A recent study has explained why this episode was so deadly. The amounts of volcanic volatile matter discharged from Siberia can’t explain the extent of the phenomenon as it is not enough to bring about mass extinction. For researchers, nearly 70% of this toxic material was actually extracted directly from the lithosphere, which explains the dramatic consequences for the climate.