Many people became aware of the risk of tsunamis only after the Indian Ocean Tsunami of December 24, 2004, which killed 220 thousand people. However, tsunamis occur every year around the world.
rnrnFigure 1.1 shows the map of earthquake centres within the recent 100 years. Large earthquakes occur mainly around the boundaries of tectonic plates which cover the earth. The major cause of tsunamis is earthquakes occurring at the edges of the plates, where subduction zones develop due to the everlasting movement of tectonic plates. Tsunamis also occur due to large marine landslides and volcanic eruptions. rn
rnrnAreas that have been attacked by tsunamis in the past are very likely to be attacked again by tsunamis in the future. For example, the subduction zone earthquakes off Tokai Coast in Japan occur at intervals of about 150 years. It should be noted, however, that the intervals of the earthquakes vary significantly depending on the geological characteristics of the subduction zones. The intervals can be estimated by historical documents of tsunami disasters or tsunami deposits in coastal areas. Earthquake geology is being developed to estimate the past and future subduction zone earthquakes.
rn rnrn?Tsunami? is a Japanese word written with two Chinese characters. ?Tsu? means harbour/port and ?nami? means wave, and therefore ?tsunami? means ?harbour/port wave? in Japanese. The naming comes from the fact that tsunamis seem to appear suddenly and become very violent in shallow areas, attacking low-lying areas that are actively used and densely populated, such as port areas. Port areas around the world have often suffered from tsunami disasters with large numbers of casualties.
rnrnrnThis report was prepared to help people in such vulnerable areas protect themselves against tsunami attacks. It is especially written for those responsible for the safety of the people and continuity of the business in such areas. Chapter 2 presents examples of damage due to tsunamis especially in ports giving them a general view of the damage that can result from a tsunami attack. Chapter 3 explains the mechanism of tsunamis from their generation to their run-up, and Chapters 4 and 5 introduce the behaviour of tsunami and its effects on port facilities. Chapter 6 presents recommendations for disaster management in ports, and Chapter 7 offers recommendations for warning and evacuation in case of a tsunami attack. Chapter 8 discusses structural countermeasures that can be implemented for protection against tsunamis. It is recommended to understand recent progress on tsunami technology from the references listed below.rn
