Seismic sea waves (tsunamis) are shallow water waves. The leading tsunami wave from the Chilean earthquake of May 22, 1960 at 19 hr 11 min 20 s G.M.T. arrived at Hobart in 12 hr. The tsunami was also recorded on tide gauges up the east coast of Australia and at Norfolk and Lord Howe Islands. The wave took 14 hr 04 min to reach Auckland, N .Z., but this is because of the low speed of the wave over the extensive submerged continental structure off the eastern coast of North Island. The tsunami was not recorded at Port Melbourne. From the travel-times the average depth of the Pacific Ocean between Tasmania and South America is 5500 m.