Know your Science
The lithosphere is the rigid, outermost layer of Earth, made up of the crust and the top part of the upper mantle. The term comes from the Greek words litho, meaning “stone”, and “sphere”. The lithosphere is the coolest and most rigid part of Earth. It’s a strong and elastic layer that sits above the asthenosphere, which is weaker and more ductile. The lithosphere is important for life on Earth in many ways, including:
- Minerals: The lithosphere is a rich source of minerals, including copper, magnesium, aluminum, and calcium.
- Nutrients: The lithosphere, along with the hydrosphere and atmosphere, provides nutrients for plant and animal life.
- Terrain: The lithosphere’s rocky terrain is essential for the biosphere.
- Volcanoes, mountains, and continents: Tectonic plates shifting within the lithosphere create volcanoes, mountains, and continents.The oceanic lithosphere is denser than the continental lithosphere because it cools, thickens, and ages as it moves away from the mid-ocean ridge. This process is called thermal contraction.