Mantle (geology)

The mantle is the thick layer of hot rock that lies beneath the Earth's crust and above the outer core. Comprising roughly 84% of Earth's volume, it extends from about 35 kilometers down to roughly 2,900 kilometers below the surface. Despite its solid appearance, the mantle behaves as a viscous fluid over geological timescales, flowing slowly in vast convection currents driven by internal heat.

These convection currents are the engine of Plate tectonics, pushing and pulling the crustal plates that shape continents and ocean basins. The mantle's composition is dominated by silicate minerals like olivine and pyroxene, with density and temperature increasing dramatically with depth. The uppermost mantle, coupled with the crust, forms the rigid Lithosphere; below that lies the plastic Asthenosphere, where rock flows more easily.

Scientists study the mantle through Seismic waves from earthquakes, volcanic eruptions, and laboratory experiments replicating extreme pressures and temperatures. Understanding mantle dynamics reveals how mountains rise, volcanoes erupt, and the very face of our planet evolves.

Related

Plate tectonics, Lithosphere, Asthenosphere, Earth structure, Volcanic activity, Seismology