A local broadband seismograph network in Honshu Island, Japan, recorded the free oscillations excited by the 1989 Macquarie Ridge earthquake, one of the largest strike-slip events in the last decade. The initial amplitude pattern of the spheroidal modes varies from station to station in the network in spite of the small differences in epicentral distance and epicenter-to-station azimuth. Theoretical amplitude of each mode depends on the earthquake mechanism and distance. The most dramatic change occurs for a pure strike-slip event near the distance of 90¿ where the initial amplitude of every odd order multiplet becomes exactly zero. This is the case for the Macquarie Ridge earthquake observed in Japan. From this sensitivity of the amplitude pattern to the epicentral distance, we can estimate the apparent centroid location by searching a minimum misfit between the observed and theoretical initial amplitudes. The apparent centroid, which is a projection of the real centroid onto the great circle path, is estimated to be 49 km from the epicenter in an azimuth of N19¿W. ¿ American Geophysical Union 1993