Erdinneren

Erdinneren, oder the Earth’s interior, denotes the collective structure beneath the planet’s surface. It includes the crust, the mantle, and the core, and its properties are inferred from seismic data, geochemistry, and high‑pressure experiments. Understanding Erdinneren is essential for explaining geodynamics, volcanism, heat flow, and the generation of Earth’s magnetic field.

The outermost shell is the crust, which comes in two primary types: continental crust, rich in granitic rocks and less dense, and oceanic crust, dominated by basalt and more dense. The boundary between crust and mantle is marked by the Mohorovičić discontinuity, or the Moho. The crust rests on the mantle, together forming the lithosphere and the underlying, more plastic asthenosphere that participates in plate tectonics.

The mantle extends to about 2,900 kilometers below the surface and is divided into upper and lower regions, with a transition zone in between. The upper mantle contains the asthenosphere, a partially molten layer that enables tectonic movement. The transition zone, around depths of roughly 410 and 660 kilometers, involves mineral phase changes that affect seismic velocities.

The core comprises a liquid outer core and a solid inner core. The boundary between the mantle and outer core is the Gutenberg discontinuity, while the boundary between the outer and inner core is the Lehmann discontinuity. The flow in the liquid outer core generates the geomagnetic field through the geodynamo, whereas the inner core remains solid due to immense pressures.

Methods of study include analysis of seismic waves, examination of xenoliths brought up by volcanism, laboratory experiments simulating extreme pressures and temperatures, and numerical models of mantle convection and dynamo action. Ongoing research refines estimates of composition, temperatures, and dynamics within Erdinneren.