What are tectonic plates?

Tectonic plates are massive slabs of the Earth's lithosphere—the rigid outer layer of the Earth—that fit together like pieces of a giant jigsaw puzzle covering the planet’s surface. These plates vary in size and include both continental and oceanic crust. They constantly move, albeit very slowly, over the more fluid layer beneath called the asthenosphere. The movement is driven by forces such as mantle convection, slab pull, and ridge push. The interaction of tectonic plates is central to the occurrence of earthquakes. As plates move, they can collide, pull apart, or slide past each other along boundaries known as faults. When stress along these boundaries builds up beyond the strength of the rocks, it is released suddenly in the form of seismic energy, causing an earthquake. Different types of plate boundaries—convergent, divergent, and transform—produce different kinds of earthquakes and geological features. For example, the Pacific Plate’s movement relative to the North American Plate causes frequent seismic activity along the San Andreas Fault in California. In summary, tectonic plates are fundamental components of Earth's geology, and their movements are the primary cause of earthquakes, shaping the planet’s surface over time.