The ground moves
Earth’s lithosphere is broken into plates that move over the mantle. Continents drift, seafloor spreads, and mountains rise at the boundaries.
Wegener’s continental drift (1912) had the shapes and the fossils, not the engine. The engine arrived with seafloor spreading, magnetic stripes, and subduction in the 1960s. Mid-ocean ridges add crust; trenches swallow it. Plates jostle at centimetres per year.
GPS now watches the motion in real time. Earthquakes and volcanoes trace the edges. The Himalaya is India still driving into Asia. The Atlantic is widening. Supercontinents have assembled and broken more than once.
No other planet we have mapped does this in the same way. Plate tectonics is Earth’s long climate and mineral machine: carbon cycling, mountain weather, ore deposits, and the occasional city-killing slip.
Caveats
- When plate tectonics started is debated (Archean vs later).
- Mantle plumes and intraplate volcanism are extra machinery, not a rival to plates.
Sources
- 1Hess H. H.. History of Ocean Basins. Petrologic Studies: A Volume in Honor of A. F. Buddington, 1962.
- 2Wilson J. T.. A New Class of Faults and their Bearing on Continental Drift. Nature 207, 1965.