1. Tsunamis Giant waves generated by an underwater disturbance that cause destruction to coastal areas Japanese for “harbour wave” Often incorrectly called “Tidal wave”

2. Tsunamis Waves will travel outward in all directions Time between wave crests may be from 5 to 90 minutes Wave speed in the open ocean will average 450 miles per hour. Heights of over 100 feet recorded

3. Tsunamis When created, it has a very long wave length and short wave height. As it approaches shallow coastal waters, length is compressed and heights are increased Wave becomes unbalanced and topples

4. Tsunamis Rapid changes in the water level are an indication of an approaching tsunami. Arrive as a series of successive crests (high water) and troughs (low water) After a severe earthquake on November 18, 1929, in the Grand Banks of Newfoundland –generated a tsunami that caused considerable damage and loss of life at Placentia Bay, Newfoundland.

14. -Triggered by a 9.3 underwater earthquake off the coast of Indonesia -Killed over 230 000 people -A series of deadly waves up to 30 m high -One of the deadliest natural disasters in human history Boxing Day Tsunami

16. Tsunamis – Kalutara, Sri Lanka- Before

17. Tsunamis – Kalutara, Sri Lanka- After

18. Tsunami - Banda Acech – Northern Sumatra - Before

19. Tsunami - Banda Acech – Northern Sumatra - After

20. Predicting Tsunamis It can be difficult to predict a tsunami A sharp swell is the first sign, followed by a receding shoreline Then the first massive wave hits. The third to eighth waves are usually the largest One of the best ways to predict a tsunami is to monitor earthquakes

21. Survive it! In groups, brainstorm and research ways to survive either an earthquake OR a tsunami. Could include structural changes to buildings, or survival kits