Charles Francis Richter (1900-1985), American seismologist. Richter was co-creator of the famous Richter earthquake scale that is named after him. The scale measures the magnitude of an earthquake, ranging from 1-9. An increase of one unit equates to a 30-fold increase in earthquake energy. This scale was devised in 1932 with Gutenberg, and has been modified several times since. He was educated at Stanford University, California. He started his PhD at Caltech, California, and later spent most of his career there (from 1937 onwards). He became Professor of Seismology there in 1952.