litosfääris

The lithosphere is the rigid, outermost shell of a terrestrial-type planet or natural satellite. It is composed of all the crust and the part of the upper mantle, along with the solid crust, that is brittle enough to fracture rather than deform plastically. The lithosphere is the coolest and least dense layer of the planet. It is broken into tectonic plates that move over the asthenosphere, the mechanically weak and ductile region of the upper mantle. The word "lithosphere" comes from the Greek word lithos, meaning "stone."

The thickness of the lithosphere varies considerably across the Earth's surface. It is generally thinner under the mid-ocean ridges and thicker under the continents. The lithosphere is divided into two main parts: the oceanic lithosphere and the continental lithosphere. Oceanic lithosphere is thinner and denser than continental lithosphere. Continental lithosphere is thicker and less dense, and it forms the continents and their submerged continental shelves. The lithosphere plays a crucial role in geological processes such as plate tectonics, earthquakes, and volcanic activity.