Plate Tectonics

By Shristi Ghosh

An Introduction

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.

The cross-section of the Earth