In addition to other provisions of this charter, a vacancy shall be deemed to exist in any elective office on the day when the officer dies, files his resignation with the city clerk, is removed from office, moves from the city, is convicted of a felony, or of misconduct in office under this charter, is judicially declared to be mentally incompetent, or is absent from three (3) consecutive regular meetings of the council, unless excused by the council for cause to be stated in the record of council proceedings.