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A team of Harvard researchers believe to have found a scientific explanation for the Sturtian snowball Earth event that enveloped the planet in a thick coat of snow. According to them, a large volcanic eruption took place in the Franklin large igneous province about the same time as the event began, prompting a global cooling.
Scientists Have Been Trying to Explain Snowball Earth for Decades
According to F.A. Macdonald and R. Wordsworth, the authors of Initiation of Snowball Earth with volcanic sulfur aerosol emissions, the Neoproterozoic Snowball Earth event happened around the same time as the Natkusiak magmatic assemblage eruption.
“We know that volcanic activity can have a major effect on the environment, so the big question was, how are these two events related,” Macdonald declared.
The first attempt at explaining the cause and effect relation between the two events came in the form of a basaltic rock decomposition theory. When basaltic rock is broken down into its two key components, calcium and magnesium, the elements start interacting with the carbon dioxide that fills our atmosphere, leading to a universal cooling process. However, the theory was soon dismissed as the process would have taken millions of years.
Next, the two attempted to find a chemical explanation for the process, looking at geological and chemical data from the Franklin large igneous province. The team found that the area is rich in sulfur sediments, the eruption having sent sulfur dioxide into the planet’s atmosphere.
When the compound reaches higher altitudes, it can efficiently act as a gaseous umbrella, blocking all incoming solar radiation. Moreover, if sulfur dioxide manages to penetrate the tropopause, it can stay up there for more than a year.
Adding the fact that the tropopause’s height is directly proportional to a planet’s global temperature – the lower the temperature, the lower the atmosphere – and taking into consideration that 717 million years ago, the Earth was significantly cooler, it is easy to prove that a massive volcanic event could have covered the planet in snow from pole to pole.
It’s also very important to note that the Franklin large igneous province was located near the Equator, the place where most of the Sun’s warmth penetrates the atmosphere.
The scientists concluded that it is important to understand that climate, on most planets, is unpredictable, large, climate-altering events happening all the time. They also proposed that the scientific community should distance itself from the simple paradigm of exoplanets.
Image Source: Flickr
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