Millions of years ago, the Earth turned into a snow globe: scientists have finally learned the reason
About 717 million years ago there was a climatic catastrophe on our planet and the temperature dropped sharply. For a long time, scientists could not find out the cause of the so-called "Sturtian glaciation", which lasted 57 million years.
According to geologists, the sharp drop in temperature could have been caused by a meteorite fall, volcanic eruption or biological activity of the Earth. Earth and Planetary Science Letters and Science Advances published the scientists' research.
Scientists tend to believe that the transformation of the Earth into a snow globe was caused by volcanic eruptions.
According to them, volcanism can cause cooling in two ways.
The first way is through volcanic eruptions, which release sulfur-rich gases and form aerosols that block sunlight and cool the planet.
The second is weathering (chemical alteration of fresh volcanic rock). Lava undergoes reactions in which the CO2 in rainwater reacts with the rocks to form minerals that fall out into the ocean.
"Sulfur aerosols linger in the atmosphere for only a few months or years. Weathering, however, is much slower and takes 1 to 2 million years before the cooling effects reach their peak," Judy Poo, lead author of the study, told Science Advances from the University of California.
Through a study of one of the largest volcanic eruptions in northern Canada in the so-called Franklin Large Igneous Province, scientists found that the initial pulse of volcanism occurred 1 to 2 million years before ice appeared on Earth. This is exactly the amount of time it takes for weathering to lead to cooling.
This supports the theory that the Earth's temperature dropped due to volcanic eruptions and weathering.
"The study highlights the power of weathering as a key driver of changes in Earth's climate, and how different components of the planet such as rocks and the atmosphere are inextricably linked," Galen Halverson, sedimentary rock geologist said.
Poo says other factors may have accelerated weathering enough to cause a climate catastrophe. To start with, all the land masses at the time were near the equator, where temperatures were warm and the surface was often flooded with rain. Lava flows also appeared during the breakup of the supercontinent Rodinia, which exposed fresh rocky surfaces to weathering and may have already begun to cool the global climate.
Earlier OBOZREVATEL told how scientists discovered the real killer of mammoths, which wiped them off the face of the Earth.