Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Data Kicks Up ’Snowball Earth’ Fight

05.12.2001


In 1998, Paul F. Hoffman and Daniel P. Schrag at Harvard University put forth a chilling description of earth’s climate some 650 million years ago. Their theory, dubbed snowball earth, held that between 750 million and 580 million years ago, ice repeatedly enveloped our planet, coating the seas from pole to pole and killing off early life almost completely. During the past few years, the idea has stirred up a great deal of debate. And new data published in the December issue of Geology only further throws snowball earth into question.



Lead author Martin Kennedy at the University of California, Riverside, and colleagues collected limestone and dolomite rocks from Precambrain glacial deposits in northern Namibia, central Australia and the North American Cordillera. When they analyzed these samples, they discovered that the ratio of the carbon isotope 13C to 12C was higher during the glaciation than after the ice had melted. This pattern, they say, suggests that the oceans supported a healthy ecosystem at the time — which would be hard to do were they frozen over.

"If there was no photosynthesis or life in the ocean, the carbon isotope values would be the same as the mantle," Kennedy says. "Only the presence of life causes a difference in those values. We did not find isotopic evidence that a global ice sheet impacted overall marine productivity. We would think that if an ice sheet covered the oceans it would have had an impact on marine production or photosynthesis and we find no carbon isotopic evidence for this. The oceans just look normal."

Kristin Leutwyler | Scientific American
Further information:
http://www.sciam.com/news/120501/2.html

More articles from Earth Sciences:

nachricht Volcanoes under pressure
18.11.2019 | Technical University of Munich (TUM)

nachricht New findings on the largest natural sulfur source in the atmosphere
18.11.2019 | Leibniz-Institut für Troposphärenforschung e. V.

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Atoms don't like jumping rope

Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.

By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...

Im Focus: Images from NJIT's big bear solar observatory peel away layers of a stellar mystery

An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.

With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...

Im Focus: New opportunities in additive manufacturing presented

Fraunhofer IFAM Dresden demonstrates manufacturing of copper components

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

Im Focus: Magnets for the second dimension

If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.

Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

 
Latest News

Structure of a mitochondrial ATP synthase

19.11.2019 | Life Sciences

The measurements of the expansion of the universe don't add up

19.11.2019 | Physics and Astronomy

Ayahuasca compound changes brainwaves to vivid 'waking-dream' state

19.11.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>