William Jason Morgan is an American geophysicist who has made seminal contributions to the theory of plate tectonics and geodynamics. He retired as the Knox Taylor Professor emeritus of geology and professor of geosciences at Princeton University. He currently serves as a visiting scholar in the Department of Earth and Planetary Sciences at Harvard University. He was born on October 10, 1935 in Savannah, Georgia, United States. From 1971 on he worked on the further development of the plume theory of Tuzo Wilson, which postulates the existence of roughly cylindrical convective upwellings in the Earth's mantle as an explanation of hotspots. Wilson originally applied the concept to Hawaii and explained the increase in age of the seamounts of the Hawaii-Emperor chain with increasing distance from the current hotspot location; however, the concept was subsequently applied to many other hotspots by Morgan and other scientists. Morgan has received many honors and awards for his work, among them the Alfred Wegener Medal of the European Geosciences Union (1983), the Maurice Ewing Medal of the American Geophysical Union (1987), the Wollaston Medal of the Geological Society of London (1994) and the National Medal of Science of the USA, award year 2002.