Feeds

'Snowball Earth': Glaciers, ice packs once met at Equator

Recent piddling glaciations were luxury

Seven Steps to Software Security

American boffins say they have discovered evidence that almost the entire world was covered in sea ice and glaciers at certain points in the remote past, during so-called "snowball Earth" periods where the polar ice sheets met at the Equator.

The 'Snowball Earth' theory explained. Credit: NSF

It were grim in the old days.

Geologists probing conditions seen in the ancient world have long considered that there was a cold spell known as the Sturtian Glaciation about 716 million years ago. However there has been disagreement in boffinry circles as to just how severe this glaciation was.

Now, researchers from Harvard uni in the States, funded by the US government, say they have found ironclad proof that there were glaciers right down on the Equator at that time. Tropical rocks from the Sturtian, which have since migrated up to remote northwestern Canada, show unmistakable signs of having been covered in big ice back then.

"This is the first time that the Sturtian glaciation has been shown to have occurred at tropical latitudes, providing direct evidence that this particular glaciation was a 'snowball Earth' event," says geology brainbox Francis Macdonald of Harvard.

"Our data also suggest that the Sturtian glaciation lasted a minimum of five million years," he adds.

"Ice may have covered the entire planet then," comments Enriqueta Barrera, federal science bigwig, "turning it into a 'snowball Earth'."

The new rock data is considered to add support to the theory that the planet has seen two runaway Snowball-Earth glaciations in the past, the Sturtian and the following Marinoan. There were also two similarly-extreme "hothouse" spells where all the ice melted, perhaps 670 and 630 million years ago. Thereafter more moderate glaciations and warmings have been seen.

The Power of One eBook: Top reasons to choose HP BladeSystem

More from The Register

next story
Bad back? Show some spine and stop popping paracetamol
Study finds common pain-killer doesn't reduce pain or shorten recovery
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
World Solar Challenge contender claims new speed record
One charge sees Sunswift travel 500kms at over 100 km/h
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
SMELL YOU LATER, LOSERS – Dumbo tells rats, dogs... humans
Junk in the trunk? That's what people have
All those new '5G standards'? Here's the science they rely on
Radio professor tells us how wireless will get faster in the real world
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.