Plate tectonic theory is a scientific explanation of the large-scale movements of the Earth's solid outer layer, the lithosphere. It explains how the lithosphere is broken into several large plates that move and interact with each other. According to the theory, the Earth's lithosphere is divided into seven major and several minor tectonic plates that move relative to one another, driven by movements in the underlying semi-liquid mantle.
The plates can interact in three main ways:
- Divergent boundary: When two plates move away from each other, magma rises from the mantle to fill the gap, creating new crust.
- Convergent boundary: When two plates collide, one plate is forced beneath the other in a process called subduction. This can lead to the formation of oceanic trenches, volcanic activity, and the creation of mountain ranges.
- Transform boundary: When two plates slide past each other, they can cause earthquakes.
The theory explains a range of geological phenomena, including earthquakes, volcanic eruptions, and the creation and movement of continents. It is widely accepted by the scientific community and forms the basis for much of our understanding of the Earth's geology.