Feeds

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

Recent piddling glaciations were luxury

Secure remote control for conventional and virtual desktops

What doesn't kill you makes you stronger - how animals got their start?

Macdonald says that glaciers on land at the Equator means solid pack ice at sea in the tropics, too.

"Climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over," he says. "So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation."

Even on Snowball Earth, however, it's thought that there must have been "refugia" where liquid surface water and at least occasional sunlight remained, as proto-animal life above the bacterial level is believed to have arisen and survived at around the time of the first, Sturtian snowballing. Macdonald considers that the big freeze may actually have stimulated early, primitive life to get its act together and begin the long process which has led to the present-day biosphere.

"The fossil record suggests that all of the major eukaryotic [other than microbial] groups, with the possible exception of animals, existed before the Sturtian glaciation," says the prof. "The questions that arise from this are: If a snowball Earth existed, how did these eukaryotes survive? Did the Sturtian snowball Earth stimulate evolution and the origin of animals?"

"From an evolutionary perspective," he adds, "it's not always a bad thing for life on Earth to face severe stress."

Macdonald and his colleagues aren't sure what triggered the Sturtian snowball effect, but note that a lot of lava came to the earth's surface at around that point, suggesting that the big chill could have been kicked off by volcanic dust darkening the skies.

The Harvard team publish their results this week in hefty boffinry mag Science. ®

Boost IT visibility and business value

More from The Register

next story
Cutting cancer rates: Data, models and a happy ending?
How surgery might be making cancer prognoses worse
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
Brit balloon bod Bodnar overflies North Pole
B-64 amateur ultralight payload approaching second circumnavigation
Galileo, Galileo! Galileo, Galileo! Galileo fit to go. Magnifico
I'm just a poor boy, nobody loves me. But at least I can find my way with ESA GPS by 2017
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
Astronomers scramble for obs on new comet
Amateur gets fifth confirmed discovery
prev story

Whitepapers

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.
5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?