In 1912 Alfred Wegener argued that the continents had once been joined, and that coastlines, fossils and rock strata showed it. The objection was not to the evidence but to the mechanism: nobody could explain how granite continents ploughed through a basalt floor. Though the evidence accumulated, for forty years the idea entered textbooks marked 'interesting but not accepted'.

The answer came from beneath rather than above. The sonar and magnetometer technology of the Second World War was turned after it to mapping the ocean floor; the maps drawn by Marie Tharp and Bruce Heezen revealed an immense rift running along the mid-ocean ridges. In 1963 Fred Vine and Drummond Matthews, and independently Lawrence Morley, noticed that the magnetic anomalies on either side of a ridge formed symmetrical stripes: new crust formed at the ridge, froze in the direction of the field at that moment, and spread outward. The repeated reversals of Earth's magnetic field had been recorded on the seafloor like a barcode.

In 1965 J. Tuzo Wilson tied the pieces together by defining transform faults; in 1967–68 Jason Morgan, Dan McKenzie and Xavier Le Pichon published the global plate model. The continents were not drifting — the plates carrying them were moving. The new framework linked earthquakes, volcanic belts, mountain building and fossil distribution to a single mechanism, and the character of the fault system across northern Anatolia was understood within it. It counts as one of the cleanest paradigm shifts in the history of science: what had been missing was never the data but the mechanism that explained it.