Tomorrow is the 69th birthday of Seiya Uyeda, a Japanese geophysicist known for his contributions to plate tectonics. From 1957 to 1964, Uyeda studied island arcs, the series of island chains along the northern and western Pacific that have deep trenches along their ocean sides. He found that the crust on the continental side of the arcs was not only warmer than the oceanic side but also had more volcanoes and earthquakes. In 1975, Uyeda and his colleague Don Forsyth proposed that oceanic crust slides down into the mantle at the trenches, a process known as subduction.
[Source: Emily McMurray, Ed., Notable Twentieth Century Scientists (Gale Research Inc., ITP, 1995).]