Zebra stripes helped move the continents

Mid-century surveys found alternating magnetic bands across oceanic rock. In 1963, Frederick Vine and Drummond Matthews—and Lawrence Morley independently—proposed that the pattern recorded magnetic reversals as fresh crust spread from ridges. Later comparison with dated reversals made the symmetry hard to dismiss.

No single observation created plate tectonics; earthquake locations, seafloor topography, geology and earlier continental-drift arguments also mattered. The stripes supplied a mechanism and a record where an older proposal had lacked both. An instrument towed over an unseen landscape helped turn moving continents from a disputed picture into a working Earth system.