When there are two oscillations in a nonlinear system, new oscillations called combination tones appear. We try to detect combination tones between the earth tides and the earth\u27s free oscillations using the long-period seismograms of the Bolivian great deep earthquake on June 9,1994 recorded by a broad band seismometer and a superconducting gravimeter installed at Syowa Station in Antarctica. The results suggest that combination tones between the free oscillations and the semidiurnal tide exist
