A sequence of over 80 earthquakes occurred in 1962 off the coast near Westport, New Zealand. The first and largest shock took place on May 10 and had a magnitude of 5.9; the next largest, on May 17, had a magnitude of 5.6. The epicentres of these two earthquakes have been accurately determined from readings at local seismograph stations; the strong crustal phases, felt effects, and arrival times of phases at overseas stations all show that the foci were shallow. Late arrivals at Australian stations indicate a lower velocity in the upper mantle beneath the Tasman Sea than is implied by the Jeffreys—Bullen Tables.