Massive Volcanic Eruptions Suck CO2 from Ancient Atmosphere, Trigger Snowball Earth Over 700M Years Ago

Massive volcanic eruptions that have devoid the atmosphere of CO2 caused Snowball Earth to occur over 700 million years ago.

Massive Volcanic Eruptions and Snowball Earth

A study has discovered that devastating volcanic eruptions may have gotten so large that they converted the world into "Snowball Earth" 717 million years ago.

A momentous volcanic eruption from Earth's ancient past likely initiated a series of chemical processes that effectively pulled CO2, or carbon dioxide, from the prehistoric atmosphere of our planet. This volcanic event, which occurred in what is now northern Canada, resulted in the formation of an expansive volcanic highland spanning around 860,000 square miles, approximately three times the size of Texas.

Subsequently, these newly formed rocks were bombarded by acid rain, triggering a chemical reaction that could have led to a remarkable consequence-global ice coverage for an astonishing 57 million years. This prolonged icy period, known as the Sturtian glaciation, was previously attributed to different factors by researchers, but the latest findings suggest that volcanic activity played a significant role in this transformative climatic event.

However, they weren't entirely sure how the explosion led to the creation of Snowball Earth.

Nothing can be explained in isolation, according to co-author and professor of geology Galen Pippa Halverson, who is from McGill University in Canada, Science reports.

CO2 Sucked Out of Ancient Atmosphere Leads to Cooling

According to a study, done by Halverson's team, that was released on June 27 in the journal Earth and Planetary Science Letters, there are primarily two ways that volcanic eruptions might chill the globe. Outbursts emit gases with sulfur-rich particles suspended in the air, which reduces sunlight and causes cooling. Weathering, a chemical process that lava rocks are particularly prone to, is another way that eruptions can change the environment.

Rainwater undergoes weathering when it interacts with the minerals in rocks to produce clays and soluble salts. Rainwater is slightly acidic because of its dissolved carbon dioxide content. CO2 is drawn out of the atmosphere and deposited in sediments that subsequently wash into the ocean during the formation of these new minerals. The elimination of the greenhouse gas CO2, causes the earth to cool.

Proof of Weathering

The team had to pinpoint the precise time of the volcanic outburst to determine what mechanism caused the Sturtian glacial. Sulfur atoms float around in the atmosphere for as long as several months to years, but it takes a million to two million years for rock weathering to cause global cooling.

The Franklin large igneous province (LIP) is a region where volcanoes have produced rocks that Halverson and her colleagues have studied. They determined the uranium and lead ratios in these crystals and used the rate of decay to determine their age. Additionally, the researchers dated rocks that had been carved out by glaciers as the Earth froze over.

According to their findings, the glacial began between one and two million years before the volcanic eruption, indicating that chemical weathering was the main reason for the Earth's cooling. The same result was reached by another study, which was published in the journal Science Advances, November 2022 issue.

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Rock Weathering in Supercontinent Rodinia

The Franklin LIP's cooling effect may have been influenced by rock weathering in other parts of the world. When the Earth's continents first came together to form the ancient supercontinent Rodinia, it was during this time that eruptions and subsequent glaciations took place. Rain frequently lashed this tropical terrain, causing more weathering along with CO2 entrapment.

The Timeline Conflict

But some specialists continue to be skeptical. Ice-scoured rocks that represent the beginning of Snowball Earth might have formed much later than presently thought, because the erosion suggests that thick ice was flowing at sea level, a process that is likely to have started several hundred thousand years ago, according to Paul Hoffman, a Harvard University emeritus professor of geology and co-author of the 2022 stud, Science reports.