Plate Tectonics
The unifying geophysical theory stating that Earth's rigid outer lithosphere is divided into major tectonic plates drifting over the ductile asthenosphere.
Governing formula
Plate Motion Velocity v_plate ~ 1–10 cm/year
SI unit
cm/year (Plate Drift Speed)
In depth
Tectonic plates interact along three main boundary types: Divergent (plates separate, creating new seafloor), Convergent (plates collide, forming subduction zones or mountain ranges), and Transform (plates slide horizontally past one another).
Examples in the real world
The collision of the Indian and Eurasian tectonic plates forming the Himalayan mountain range.