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Why do continents move and drift apart? Over the past century, geologists have uncovered that plate tectonics is the fundamental engine behind continental drift. The concept, first proposed by Alfred Wegener in the early 20th century, has evolved into the robust, evidence‑based theory that explains how supercontinents have broken apart and re‑assembled over billions of years.
Earth’s 4.5‑billion‑year history features a succession of supercontinents. Pangaea, the most recent, formed roughly 300 million to 100 million years ago during the Permian period. Prior to that, the Triassic epoch (about 200 million years ago) saw the split of the planet into Laurasia in the north and Gondwana in the south. These ancient configurations help scientists reconstruct the movement of today’s continents.
Wegener’s original hypothesis, rejected as pseudoscience during his lifetime, gained traction in the 1950s when mounting evidence—such as matching coastlines, fossil records, and geological strata—supported his ideas. The theory was later refined into plate tectonics, which attributes continental motion to the dynamics of lithospheric plates floating on the asthenosphere.
Earth’s lithosphere is divided into tectonic plates that move at roughly one inch (2.5 cm) per year. Driven by convection currents, mantle heat, and variations in temperature, plates slide over one another, collide, or separate. This motion reshapes coastlines, forms ocean basins, and triggers volcanic activity along plate boundaries.
Modern geodetic instruments, such as GPS and satellite radar, now measure these subtle shifts in real time, confirming the predictions of plate tectonics.
