The Earth's core is the innermost layer of the planet and is separated into two distinct parts: a solid inner core and a liquid outer core. Despite being extremely inaccessible, the core is a subject of extensive research because of its profound influence on Earth's geology, magnetic field, and heat flow.
The Inner Core
The inner core is a solid sphere primarily composed of iron and nickel. It is under immense pressure and operates at extremely high temperatures, estimated to be between 5,200 and 6,700 degrees Celsius (9,392 and 12,092 degrees Fahrenheit). The pressure at this depth keeps the material solid despite the high temperature.
|
Composition |
State of Matter |
Temperature Range |
Radius (Approx.) |
|---|---|---|---|
|
Iron, Nickel |
Solid |
5,200–6,700°C |
1,220 km |
The Outer Core
The outer core is a layer of molten iron and nickel that surrounds the solid inner core. Convection currents within this liquid layer are responsible for generating Earth's magnetic field (the geodynamo). This magnetic field shields the planet from harmful solar radiation.
Key properties of the outer core include:
- Composition: Predominantly liquid iron and nickel.
- Movement: The flow of this liquid metal creates Earth's magnetic field.
Core-Mantle Boundary
The boundary between the outer core and the overlying mantle is a significant area of research known as the Core-Mantle Boundary (CMB) or the Gutenberg discontinuity. This region plays a critical role in heat transfer from the core to the mantle, influencing mantle plumes and tectonic activity.