11454Huge stores of oxygen found deep inside Earth
- Oct 1, 2007URL to an interesting article in MSNBC
One possible explanation as to why aliens haven't come calling - majorite
may not be common on other worlds
First few paragraphs
A mineral that acts like a sponge beneath Earth's surface stores more oxygen
than expected, keeping our planet from becoming dry and inhospitable like
_Mars_ (http://www.msnbc.msn.com/id/21082196/#) .
The key to the abundant _oxygen_
(http://www.livescience.com/environment/070927_earth_oxygen.html) storage is the mineral majorite, which exists deep
below Earth's surface in the mantle. Without the oxygen stockpile, Earth would
probably be a barren planet hostile to life, authors of a study suggest in the
Sept. 27 issue of the journal Nature.
The researchers examined majorite in the lab under conditions mimicking the
Earth's deep interior and also near the planet's surface. The results showed
that under deep-Earth conditions of high temperature and pressure, majorite
stores large amounts of oxygen. When the temperature and pressure were
decreased, as occurs near Earth's surface, the majorite decomposed and released the
_oxygen_ (http://www.livescience.com/animals/070813_big_bugs.html) .
"The Earth's upper mantle can store, therefore, much more oxygen than
previously expected," said lead author Arno Rohrbach, a doctoral student at the
University of Bonn's Mineralogical Institute in Germany.
In nature, the deep stores of oxygen (in the form of majorite) ride
convection currents up toward Earth's surface. Along the way, the pressure and
temperature decrease, and at some point majorite breaks down.
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