By Shristi Ghosh
Plate tectonics (from the Late Latin tectonicus, "pertaining to building") is a scientific theory that describes the large-scale motions of Earth's crust. The model builds on the concepts of continental drift, developed during the first few decades of the 20th century.
A detailed map of plate boundaries
The main features of plates
- These plates are in constant motion travelling at a few centimetres per year.
- The ocean floors are continually moving, spreading from the centre and sinking at the edges.
- Convection currents beneath the plates move the plates in different directions.
- The source of heat driving the convection currents is radioactive decay which is happening deep in the Earth.