Explosive Underwater Volcanoes May Have Triggered 'Snowball Earth' Event

Posted: Jan 20 2016, 9:48pm CST | by , in News | Latest Science News


Explosive Underwater Volcanoes May Have Triggered 'Snowball Earth' Event
Extensive underwater volcanism during ridge spreading led to rapid alteration of volcanic deposits and major changes in ocean chemistry. Credit: Gary Hincks

It has been assumed that Earth underwent an extreme glacial period around 720 to 640 million years ago when thick sheets of ice covered almost the entire surface of the earth and turned it into a ‘Snowball Earth.’ 

Now research suggests that explosive underwater volcanoes were the main driving force behind that extreme glaciation.

Researchers are not sure about the causes of this extreme cooling. It has been widely believed that the breakup of supercontinent Rodinia, which contained most or the Earth’s entire landmass, increased the run-off from river into the ocean. This changed ocean chemistry and reduced carbon dioxide in the atmosphere, which in turn, increased the ice coverage and locked the Earth into deep freeze.

Vast ice sheets covering the surface reflected the sunlight away from the Earth and ceased all weather changes until carbon dioxide released from land-based volcanic activity warmed the atmosphere and rapidly melted the ice cover.

Researchers believe that the breakup of supercontinent Rodinia may have released huge amount of volcanic chemicals that brought changes in oceans, removed CO2 from the atmosphere and led to cooling the planet. 

"When volcanic material is deposited in the oceans it undergoes very rapid and profound chemical alteration that impacts the biogeochemistry of the oceans,” said lead author Tom Gernon from University of Southampton. “We find that many geological and geochemical phenomena associated with Snowball Earth are consistent with extensive submarine volcanism along shallow mid-ocean ridges."

His model does not explain one of the most puzzling questions; how hundreds of metres thick deposits known as 'cap carbonates', laid in warm waters after Snowball Earth events. 

Researchers suggest that when Rodinia broke up, lava erupted and produced the large amount of glassy pyroclastic rock called hyaloclastite and turned the oceans very rich in calcium, magnesium, silicon and phosphorus.

Gernon explained: "We calculated that, over the course of a Snowball glaciation, this chemical build-up is sufficient to explain the thick cap carbonates formed at the end of the Snowball event.” 
The study also indicates how animal life began on Earth millions of years later.

You May Like


The Author

Hira Bashir covers daily affairs around the world.




Leave a Comment

Share this Story

Follow Us
Follow I4U News on Twitter
Follow I4U News on Facebook

You Also Like


Read the Latest from I4U News