Mannerliikkeet

Mannerliikkeet refers to the geological processes that cause the Earth's lithosphere to move and interact. The lithosphere, the rigid outer shell of the Earth, is broken into several large and small pieces called tectonic plates. These plates float on the semi-fluid asthenosphere beneath them, which is part of the Earth's upper mantle. The movement of these tectonic plates is driven by convection currents within the Earth's mantle. Hotter, less dense material rises from deep within the Earth, cools as it reaches the upper mantle, and then sinks back down, creating a continuous circulation.

As these convection currents move, they exert forces on the overlying tectonic plates, causing them to drift across the Earth's surface. This movement is slow, typically only a few centimeters per year, but over geological timescales, it has profound effects on the planet's surface. The interactions between these plates at their boundaries are responsible for many of Earth's most dramatic geological features and phenomena.

There are three main types of plate boundaries. At divergent boundaries, plates move away from each other, leading to the formation of new crust, often seen at mid-ocean ridges. At convergent boundaries, plates collide. This can result in one plate being forced beneath another (subduction), creating deep ocean trenches and volcanic arcs, or in the collision of two continental plates, forming large mountain ranges like the Himalayas. At transform boundaries, plates slide past each other horizontally, generating significant seismic activity like earthquakes. The continuous motion and interaction of these plates, known as plate tectonics, is a fundamental concept in understanding Earth's geology.