Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




ICE WORLD
Research shows how life might have survived 'snowball Earth'
by Staff Writers
Seattle WA (SPX) Oct 12, 2011


Many scientists believe Earth became a giant snowball two or three times between 800 million and 550 million years ago, with each episode lasting about 10 million years.

"Under those frigid conditions, there are not a lot of places where you would expect liquid water and light to occur in the same area, and you need both of those things for photosynthetic algae to survive," said Adam Campbell, a University of Washington doctoral student in Earth and space sciences.

A long, narrow body of water such as the Red Sea, about 6.5 times longer than it is wide, would create enough physical resistance to advancing glacial ice that the ice sheet likely could not make it all the way to the end of the sea before conditions cause the ice to turn to vapor. That would leave a small expanse of open water where the algae could survive.

"The initial results have shown pretty well that these kinds of channels could remain relatively free of thick glacial ice during a 'snowball Earth' event," Campbell said.

He examined the issue using an analytical model that applied basic principles of physics to a simple set of atmospheric conditions believed to have existed at the time.

The results were published Saturday (Oct. 8) in Geophysical Research Letters. Co-authors are Edwin Waddington and Stephen Warren, UW professors of Earth and space sciences.

Many scientists believe Earth became a giant snowball two or three times between 800 million and 550 million years ago, with each episode lasting about 10 million years.

These all preceded the Cambrian explosion about 530 million years ago, when life on Earth rapidly expanded, diversified and became more complex.

But simple photosynthetic plankton turn up in the fossil record before and after the "snowball Earth" events, leading scientists to wonder how that could happen if Earth's oceans were completely encased in ice.

Campbell said it is assumed the algae survived these episodes, "unless they re-evolved each time, which creates a whole different problem for evolutionary biology."

He chose the Red Sea as an example because it is formed from a tectonic process called continental rifting, a process known to have existed at the time of the snowball Earth events, and it lies in an arid region between Egypt and the Arabian Peninsula.

Campbell noted that in a snowball Earth event, the open water in such a sea wouldn't have lasted long if it didn't have a way of being replenished - if, for example, the glacial ice acted as a dam and cut off the influx of additional sea water. The open water had to exist on the order of 10 million years for the algae to survive.

"Over 10 million years, you could evaporate the deepest lake in the world," Campbell said. "If you're in a desert, you'd have to have a supply of sea water."

The paper is available here.

.


Related Links
University of Washington
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ICE WORLD
Rising CO2 levels at end of Ice Age not tied to Pacific Ocean
Corvallis, OR (SPX) Oct 07, 2011
At the end of the last Ice Age, atmospheric carbon dioxide levels rose rapidly as the planet warmed; scientists have long hypothesized that the source was CO2 released from the deep ocean. But a new study using detailed radiocarbon dating of foraminifera found in a sediment core from the Gorda Ridge off Oregon reveals that the Northeast Pacific was not an important reservoir of carbon duri ... read more


ICE WORLD
Subtly Shaded Map of Moon Reveals Titanium Treasure Troves

NASA's Moon Twins Going Their Own Way

Titanium treasure found on Moon

NASA Invites Students to Name Moon-Bound Spacecraft

ICE WORLD
Video Documents Three-Year Trek on Mars by NASA Rover

Mars Express: Current flows and 'islands' in Ares Vallis

Opportunity is on the Move Again

Tracing the Canals of Mars

ICE WORLD
In Response to New York Bait-And-Switch, Brown Calls on NASA to Reevaluate Shuttle Site Placement

Iran failed with space monkey launch: report

UN highlights everyday benefits from space science and technology

Shot US lawmaker honors astronaut husband

ICE WORLD
China's first space lab module in good condition

Takeoff For Tiangong

Snafu as China space launch set to US patriotic song

Civilians given chance to reach for the stars

ICE WORLD
It's All in the Mix With Fluid Physics in Space

DLR ROKVISS robotic arm returns from space

Commercial space deliveries 'within months': NASA

Private US capsule not to dock with ISS

ICE WORLD
Indian-French satellite put into orbit

Chinese rocket sends French telecom satellite into space

On-time preparations continue for Soyuz' milestone mission from French Guiana

US telecoms satellite reaches designated orbit

ICE WORLD
Astronomers Find Elusive Planets in Decade-Old Hubble Data

University of Texas-led Team Discovers Unusual Multi-Planet System with NASA's Kepler Spacecraft

Heavy Metal Stars Produce Earth-Like Planets

Doubts Over Fomalhaut b

ICE WORLD
German satellite hurtles towards Earth: officials

Asia powers PC rebound in computer gaming industry

Global computer sales slow as people turn to tablets

Northrop Grumman Demonstrates HAMMR "On-the-Move" Radar at Yuma Proving Grounds




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement