Saturday, May 21, 2011
This melting could actually be linked to activity at the Earth's surface, the researchers said, and added that the discovery could help explain how the core generates the planet's magnetic field.
The Earth's inner core is a ball of solid iron about 1,500 miles wide, about the same size as the moon. This ball is surrounded by an outer core made up mostly of liquid iron-nickel alloy, a highly viscous mantle layer and, topping it off, a solid crust that forms the surface of the planet.
As the Earth cools from the inside out, the molten outer core is slowly freezing. This is leading the solid inner core to grow at a rate of about 1 millimeter per year.
Posted by No6 at 08:17