While it is unlikely that man will ever devise a means of preventing tsunamis more commonly known in the West by the misnomer tidal waves scientists today are constantly adding to our knowledge of their nature sources and causes and through the development of highly refined technical instrumentation are making possible early warning systems that already even in these early stages are proving of significant value In October 1969 an International Symposium on Tsunamis and Tsunami Research was held at the East West Center University of Hawaii Participants included representatives from Austalia Canada Germany Japan New Zealand U S S R and the U S A Sponsored jointly by the International Union of Geodesy and Geophysics Tsunami Committee and the East West Center the major seminars were devoted to 1 Seismic Source and Energy Transfer 2 Tsunami Instrumentation 3 Tsunami Propagation and Run up This volume contains more than 30 of the papers presented at that Symposium Recent developments and future plans for the Pacific Tsunami Warning System are included