The earthquakes that caused these tsunamis are: Prince William Sound, Alaska, 1964, magnitude 9.2; Chile, 1960, magnitude 9.5; Alaska, 1946, magnitude 7.3; Puerto Rico/Mona Rift, 1918, magnitude 7.3 to 7.5; Virgin Islands, 1867, magnitude undetermined; Cascadia, 1700, magnitude 9; and Puget Sound, 900, magnitude 7.5. Map not to scale. Earthquakes generally occur on three types of faults: normal, strike-slip, and reverse (or thrust). Tsunamis can be generated by earthquakes on all of these faults, but most tsunamis, and the largest, result from earthquakes on reverse faults. Tsunami Types. There are three (3) broad types of tsunamis: Local Tsunami. This is a tsunami where its destructive effects are experienced on coasts within 100 km from the source of the tsunami. In such cases, the travel timefor the tsunami is generally less than one (1) hour. The results suggest that New Zealand can expect a tsunami of 16.4 feet (5 m) approximately every 77 years, with a wave of at least 49.2 feet (15 m) approximately every 580 years. Tsunamis over 3.3 There are three distinct types of tsunami. The type you encounter depends on the distance you are from the place where it is generated. Distant tsunami: Are generated from a long way away, such as from across the Pacific in Chile. In this case, we will have more than three hours warning time for New Zealand. Tamon Suzuki In deep ocean, tsunami waves may appear only a foot or so high. But as they approach shoreline and enter shallower water they slow down and begin to grow in energy and height. The Tsunami "Wave Train" Many people have the mistaken belief that tsunamis are single waves. They are not. Instead tsunamis are "wave trains" consisting of multiple waves. The chart on this page is a tidal gauge record from Onagawa, Japan beginning at the time of the 1960 Chile earthquake. SDBsBd1.