[meteorite-list] Meteorites 'Cause Volcanic Eruptions'
From: Jerry <grf2_at_meteoritecentral.com>
Date: Wed, 10 Sep 2008 20:10:47 -0400 Message-ID: <8CA0E70386E94F4589AA6377EFA1E0DE_at_Notebook> We've gota love this!!!!!!!!!!!!! Where are those immense Deccan Volcanic flats that accounted for Extinction? India?? Jerry Flaherty ----- Original Message ----- From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov> To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com> Sent: Wednesday, September 10, 2008 1:46 PM Subject: [meteorite-list] Meteorites 'Cause Volcanic Eruptions' > > http://www.inthenews.co.uk/news/healthandscience/science/meteorites-cause-volcanic-eruptions-$1239971.htm > > Meteorites 'cause volcanic eruptions' > In The New (United Kingdom) > September 10, 2008 > > Violent volcanic eruptions witnessed from the dawn of time to the > present day could all have been prompted by meteorite strikes billions > of years ago. > > Geologists are presenting new evidence that contradicts the belief the > gas that causes volcanoes to erupt - 'light' helium - came to Earth via > its gravitational pull. > > Volcanic eruptions occur when the gas, which arrived when the world was > in a molten state and is trapped in the deep Earth, melts. > > But University of Manchester scientists say that the 'fingerprint' left > by the 3He isotope does not match solar nebula but instead meteorites. > > "We have shown that the neon gas fingerprint expected for the captured > solar nebula model is not matched," Professor Chris Ballentine said. > > "Instead we have found a meteorite signature, which suggests the massive > early atmosphere is not trapped by gravitational attraction as > originally thought but a result of meteorites spewing out gas on impact." > > Prof Ballentine and his team also identified a second signature, > obtained via studying CO2 gas from the Colorado Plateau, which is > identical to seawater. > > "The only explanation for this is that seawater trapped in ocean crust > is being driven back down into the deep Earth in a tectonic process > called subduction," he explained. > > Previous thinking had stated that water at these depths would be > impossible due to it melting during the subduction process. > > "This process has the potential to fundamentally change how scientists > think Earth has behaved over time. Even a little bit of water added to > rock in the deep earth makes it more plastic and allows movement of > tectonic plates sitting on top to be quicker," Prof Ballentine added. > > "The source and fate of atmospheres and water on planets is central to > understanding the origin of life and the conditions that lead to our own > planet looking as it does today. Our work provides evidence that changes > our big picture understanding of how planetary systems acquire their > volatile elements. > > ______________________________________________ > http://www.meteoritecentral.com > Meteorite-list mailing list > Meteorite-list at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Wed 10 Sep 2008 08:10:47 PM PDT |
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