 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Research Supports 'Snowball Earth' Theory
UPI Correspondent New Haven (UPI) Nov 02, 2006 A U.S. study finds Earth's magnetic field has changed little during 2 billion years, lending support to the "Snowball Earth" hypothesis. The finding by David Evans of Yale University and colleagues was previously assumed, rather than tested. The Earth's magnetic field leaves a tell-tale signature in certain rocks, which can be used to infer information about the latitude at which they formed, Evans said. But if the early Earth's magnetic field was markedly different to today's axial dipolar field, some of those interpretations could be off the mark. Evans compiled a global database of evaporite rocks dating to 2 billion years. He found the rocks' magnetic properties suggest that, as now, the Earth's magnetic field was predominantly an axial dipole on average, suggesting the Neoproterozoic "Snowball Earth" was probably shrouded in ice. The research is detailed in the current issue of the journal Nature.
Source: United Press International Community Email This Article Comment On This Article Related Links Yale University Explore The Early Earth at TerraDaily.com Explore The Early Earth at TerraDaily.com
Learning To Live With Oxygen On Early Earth
Washington DC (SPX) Oct 17, 2006Scientists at the Carnegie Institution and Penn State University have discovered evidence showing that microbes adapted to living with oxygen 2.72 billion years ago, at least 300 million years before the rise of oxygen in the atmosphere. The finding is the first concrete validation of a long-held hypothesis that oxygen was being produced and consumed by that time and that the transition to an oxygenated atmosphere was long term. |
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights 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 SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
