2012-05-28. Earth's Core - The Enigma 1,800 Miles Below Us

posted May 31, 2012, 1:03 PM by Lisa Ou   [ updated May 31, 2012, 1:06 PM ]
 | by Natalie Angier, The NY Times. An article relevant to GSS Energy Flow chapter 3. Excerpt: Geologists have long known that Earth’s core, some 1,800 miles beneath our feet, is a dense, chemically doped ball of iron roughly the size of Mars and every bit as alien… Researchers have also known that the core’s heat helps animate the giant jigsaw puzzle of tectonic plates floating far above it, to build up mountains and gouge out seabeds. At the same time, the jostling of core iron generates Earth’s magnetic field. Now it turns out that existing models of the core, for all their drama, may not be dramatic enough. Dario Alfè of University College London and his colleagues presented evidence that iron in the outer layers of the core is frittering away heat through the wasteful process called conduction at two to three times the rate of previous estimates. The theoretical consequences of this discrepancy are far-reaching. The scientists say something else must be going on in Earth’s depths to account for the missing thermal energy in their calculations…. Read more: http://www.nytimes.com/2012/05/29/science/earths-core-the-enigma-1800-miles-below-us.html