Scientists have proposed a new mechanism for the mass extinction of life on Earth 440 million years ago

440 million years ago, the Earth experienced a mass extinction event that led to the disappearance of about 85 percent of animal species, and international academics have debated the cause of extinction for more than 30 years. Recently, shen Yan'an research team of China University of Science and Technology used new methods to study that the volcanic eruption caused by climate change is the real cause of the mass extinction, this study is also of enlightenment to the analysis of modern global climate change. The results were published in nature Communications, an international authoritative academic journal.
since the Camsoon outbreak more than 500 million years ago, there have been five mass extinctions on Earth, the first of which occurred at the end of the Otau period 440 million years ago. All animals lived in the ocean at the time, and invertebrates such as Nautilus, Penstone and Coral prospered like never before, but mass extinctions wiped out about 85 percent of the species. Traditional studies have suggested that the "two-act" climate uphealy changed to lead to mass extinction when the Earth entered a glacial period and then the oceans were deprived of oxygen due to rising temperatures at the end of the glacial period.
, however, there is growing evidence that the extinction of the "two-act" life at the end of the Otau period was not entirely consistent with the formation and melting times of glaciers, which was debated by the international academic community.
Recently, Shen Yan'an task force opened up new ideas, they found yellow iron ore in southern China with the same era of mass extinction, the sulfur isotopes in it for high-precision analysis, proposed that the volcanic eruption triggered and driven the new mechanism of mass extinction events.
their study found that volcanic eruptions at the end of the Otau period transported large amounts of sulfur dioxide, hydrogen sulfide, etc. to an altitude of 20 km, reaching the stratosphere of the atmosphere and forming a "aerosol layer" dominated by sulfates.
", the aerosol layer 'intercepts' the sun's heat and cools the planet. But after a while, the sulfates in the aerosol layer will 'drop' to the ground, and the greenhouse gases released by the volcano will gain the upper hand, which in turn will cause the earth to warm sharply. Shen Yan'an said that it is this "cold and hot" repeated alternating led to the mass extinction of life. The different chemical reactions produced by "one cold, one heat" will sink to the surface with acid rain and be preserved in rocks, becoming the "key" to solving the puzzle retroactively hundreds of millions of years later.
satellite observations show that the concentration of sulfates in the Earth's atmospheric strata has been increasing for nearly 50 years. Some believe it was caused by human emissions, while others believe it was caused by modern volcanic eruptions. Shen Yan'an believes that high-precision sulfur isotope analysis can provide a means to seek causes and countermeasures.