How does plate tectonics shape Earth?
Plate tectonics explains how Earth's rigid outer shell is divided into moving pieces and how major landforms develop through their motion.
Formation process and geographic mechanism
Lithospheric plates move over the warmer, slowly deforming asthenosphere at rates commonly measured in centimeters per year. Mantle circulation, gravitational ridge push and the pull of sinking slabs all contribute. Extension, compression or sideways shear accumulates along boundaries. Earthquakes, volcanic belts, ocean floors and mountain systems are strongly associated with these margins.
Spatial outcomes, measurement and management
At convergent boundaries an oceanic plate may subduct or continents may collide and thicken the crust; divergent boundaries create new oceanic crust; transform margins slide sideways. Plate interiors are not perfectly inactive, and old faults can reactivate. Regional hazard depends not only on boundary type but also fault geometry, movement rate, ground conditions and settlement patterns.