Whose observations first linked earthquakes to plate tectonics?

Canadian geophysicist John Tuzo Wilson was one of the key figures in establishing plate tectonics in the 1960s. By comparing earthquake belts, volcano chains, and seafloor features, he helped explain that the Earth's crust is broken into moving plates. This framework showed why major earthquakes cluster around plate boundaries such as the Pacific Ring of Fire. Wilson's ideas also helped explain transform faults, which generate frequent shallow earthquakes. Plate tectonics became the unifying theory of modern geology by the late 1960s.