The lithosphere is separated into large, fragmented pieces known as tectonic plates.
These tectonic plates are not a single, continuous shell. Instead, they are like pieces of a cracked eggshell that "float" on the semi-molten asthenosphere beneath. This separation allows the plates to move and interact with each other, causing various geological phenomena.
Tectonic Plates: The Fragments of the Lithosphere
- What are they? Tectonic plates are massive, irregularly shaped slabs of solid rock, generally composed of both continental and oceanic lithosphere.
- Movement: These plates are constantly in motion, albeit very slowly (typically a few centimeters per year). This movement is driven by convection currents in the Earth's mantle.
- Boundaries: The boundaries between these plates are where most geological activity occurs, such as:
- Earthquakes: Caused by the sudden release of energy when plates slide past, collide with, or move under each other.
- Volcanoes: Often formed at convergent plate boundaries (where plates collide) or divergent plate boundaries (where plates move apart).
- Mountain Building: Occurs when plates collide and the crust buckles and folds.
- Examples: Well-known tectonic plates include the Pacific Plate, the North American Plate, the Eurasian Plate, and the African Plate.
In summary, the lithosphere is separated into distinct tectonic plates that interact with one another, leading to various geological events and shaping the Earth's surface.
