The “double blast effect” turned the Earth into a giant ball of ice

The Sturtian Ice Age dominated Earth for 57 million years. Researchers have now discovered why it persists for so long.

SYDNEY – About 700 million years ago, the Earth was almost entirely covered in ice. For 57 million years, the so-called Sturtian Ice Age kept the planet in its icy grip. This did not bother people or animals at that time, because there were none yet. However, this time is particularly exciting for research. “Imagine if the Earth were almost completely frozen over,” says Adriana Dutkiewicz, a scientist at the University of Sydney. “This is exactly what happened about 700 million years ago: the planet was covered in ice from the poles to the equator and temperatures dropped.”

The question of what caused this extreme ice age, known as the Sturtian Ice Age, and why it lasted an incredible 57 million years, has long been a mystery to science. “Various reasons have been proposed for the beginning and end of this extreme ice age, but the most puzzling is why it lasted 57 million years, a time period that is difficult for us humans to imagine,” Dutkiewicz says.

Why was the Earth an ice ball for so long?

But now it seems that Dutkiewicz's research team has found an answer to this mystery. “We now think we've solved the puzzle,” Dutkiewicz says, adding: “Volcanic carbon dioxide emissions are historically low, which was facilitated by the weathering of a large pile of volcanic rock in what is now Canada; a process that absorbs atmospheric carbon dioxide.” And the study was In the specialized magazine geology published.

The research group used a model that depicts the evolution of continents and oceans after the breakup of the ancient supercontinent Rodina. I combined this with a computer model that calculates the release of carbon dioxide from underwater volcanoes along mid-ocean ridges. The team found that the beginning of the Sturtian Ice Age coincided exactly with a historic decline in volcanic carbon dioxide emissions. Carbon dioxide emissions remained relatively low throughout the Ice Age.

Volcanoes released less carbon dioxide – and the Earth cooled

Dietmar Müller, co-author of the study, explains in A notice: “Geology determined the climate at that time. We believe that the Sturtian Ice Age was caused by a double eruption effect: the reorganization of tectonic plates reduced the degassing of volcanic gases to a minimum, while at the same time a continental volcanic province in Canada began to erode, Resulting in the consumption of atmospheric carbon dioxide in the process.

The result was a sharp decline in carbon dioxide in the atmosphere. “The carbon dioxide content in the atmosphere has fallen to the level at which ice begins to form – which, according to our estimates, is less than 200 parts per million, less than half the current value,” explains Müller.

The Earth will become hotter instead of becoming an ice ball again

Despite the fact that Earth is currently on a path toward declining volcanic carbon dioxide emissions, scientists aren't worried that the planet will revert to an ice ball any time soon. Instead, the focus is on the effects of global warming, such as melting glaciers, rising sea levels, and increasing temperatures. A recent study shows that Earth could evolve into the supercontinent Pangea Ultima within the next 250 million years. The huge landmass is said to be so hot that mammals could become extinct.

Dutkiewicz emphasizes the importance of understanding geoclimatic changes and warns about the speed of human-caused climate change: “Whatever the future holds, it is important to know that geoclimatic changes such as those studied here are very slow. According to NASA, human-caused climate change is occurring Ten times faster than we've ever seen before. (unpaid bill)

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