There is created the office of senior judge of the superior courts. Any judge of the superior court who was appointed judge of the superior courts, emeritus prior to December 31, 1976, is redesignated as senior judge of the superior courts effective December 31, 1976. Any judge of the superior courts who is eligible for appointment as judge of the superior courts, emeritus on December 31, 1976, or who becomes eligible after that date shall be designated as senior judge of the superior courts upon accepting such appointment.