The PKP waves of the 1994 deep Bolivian earthquake (Mw = 8.3) recorded by the dense short-period seismic array in Taiwan were used to make direct measurements of seismic source radiation. Employing array stacking technique, those data were used to reconstruct the time function of the source rupture. The well-resolved frequency content of this source time function was from the period of 1 to 10 seconds and, to resolve the rupture properties, it provided source information at higher frequencies than that in previous studies from global seismic network data. Rupture time analysis identifies four asperities in the array observations, and the initial rupture time of each asperity correlates well with results from previous studies using global network data. The analysed results of this study also indicate that, unlike other asperities, the two major ones did not release as much high frequency energy. However, based on the limited broadband observations in Taiwan, the long-period energy was normally released. This study concludes that this can be well explained by the lubrication of fault during the great earthquake. Several deep earthquake mechanisms have been discussed for this special rupture characteristic, and none may be fully ruled out.