The Earth inner core is located below the outer core as it is its deepest and hottest geological layer. There, temperatures range from about 6,000 to 9,000° F (3,000°/5,000° C). According to the scientific theories, these extremely high temperatures of the center of the Earth are a leftover from the origin of the planet some 5.5 billion years ago, when Gea was a chaotic ball of fire. Over hundreds of millions of years, the Earth’s surface cooled down but the core is still real hot.
Despite its age, the inner core still plays a key role in altering and shaping the planet, even on a daily basis. Its heat fuels the convection forces in the mantle, causing tectonic plates movement and collisions and giving birth to violent volcanoes. According to some scientific evidence, the inner core spins around on its own inside the Earth, as if it were a small planet inside a larger one. This rotation of the inner core would have some effect on the planet’s magnetic field. However, no scientist knows its real impact with exact certitude.
Characteristics
The Earth inner core is a solid sphere which measures 750 miles across (1210 km), which is the size of the planet’s moon. In contrast with the other geological layers of the Earth, it is a dense ball of metal. Since it contains no other layers inside, it is really the center of the Earth. About 90% of the inner core is composed mostly of iron, with a low percentage of nickel, with the rest 10% being other metallic and non-metallic elements. Unlike the outer core, it is not molten but solid, because it is under great amount of pressure. This pressure is 14 million times the pressure exerted on humans at the Earth’s surface.
Below, a drawing of the Earth’s layers showing the inner and outer core.
