W. Jason Morgan

American geophysicist whose late 1960s work related the magnetic anomalies on both sides of mid-ocean ridges to seafloor spreading and plate tectonics; the plate tectonics theory he published in 1968 has been called one of the major milestones of 20th century American science. From 1971 he developed Tuzo Wilson's plume idea into the theory of convection plumes in the lower mantle as the explanation of hotspots, and he spent his career at Princeton with a late visiting post at Harvard.