Mantellkonveksjon

Mantellkonveksjon refers to the slow churning motion within the Earth's mantle, a thick layer of silicate rock situated between the crust and the core. This movement is driven by heat emanating from the Earth's core and the radioactive decay of elements within the mantle itself. These heat sources create temperature differences, causing hotter, less dense material to rise and cooler, denser material to sink, forming convection currents.

These currents are incredibly slow, moving at rates comparable to fingernail growth, typically a few centimeters per year. However, over geological timescales, this continuous circulation plays a fundamental role in shaping the Earth's surface. Mantle convection is the primary driving force behind plate tectonics, the theory that describes the movement and interaction of the Earth's lithospheric plates.

As convection currents rise towards the surface, they can cause the crust to thin, creating rift valleys and mid-ocean ridges where new oceanic crust is formed. Conversely, where currents sink back into the mantle, they can pull plates downwards, leading to the formation of deep ocean trenches and volcanic activity associated with subduction zones. The dynamic process of mantellkonveksjon is thus crucial for volcanic eruptions, earthquakes, and the long-term evolution of continents and oceans.