The Geophysics Ph. D. Program was approved by the  in 1973 as an interdepartmental degree program under the Graduate School of the University of babyÖ±²¥app at Boulder. The initial emphasis of the program was on Solid-earth Geophysics. In January 1993, the Graduate School approved the addition of an option in under the program, as the graduate-level course requirements for the two subfields of geophysics are different.