A study ofT-phases on Tasmanian seismograms has shown that there is a precise regional distribution of earthquakes from which theT-phase is recorded in Tasmania. Factors that influence these recordings appear to be: (1) the effect of bathymetry on the So far channel; (2) the length of the land path before energy injection into the Sofar channel; (3) efficiency of energy injection into the channel; and (4) diffraction ofT-waves around submarine ridges. At the Tasmanian continental margin, the energy is converted into P-wave form which is propagated across Tasmania with velocity 5.9 km per sec and recorded at the stations of the Tasmania University Seismic Net.