For questions about the Earth's core. The center of the Earth is primarily iron-nickel.

For questions about the Earth's core.

Seismic refraction data has shown that the Earth has a central core surrounded by a , which in turn is surrounded by the relatively thin .

Following the chonditic model of the Earth and other evidence (eg. mass distribution, active magnetic field), the core is primarily composed of iron and nickel. The inner core is ~1220 km diameter and solid due to high pressure. This is surrounded by the liquid outer core which is ~2260 km thick. The solid:liquid boundary produces a strong seismic reflector and S waves do not pass through the outer core.

The outer core is actively convecting and is believed to act as a 'self exciting dynamo' which produces the Earth's active magnetic field.