Core-mantle boundary

The core-mantle boundary is the layer where Earth's dense, iron-rich core meets the overlying semi-solid mantle. Located about 2,900 kilometers beneath the surface, this boundary marks a transition in composition, physical state, and temperature. The core is extremely hot and liquid or semi-liquid, while the mantle is viscous and solid on human timescales. This boundary influences Earth's magnetic field and heat transfer, shaping geological activity such as earthquakes and volcanic eruptions. It’s a crucial interface that helps scientists understand Earth's internal structure and dynamic processes.