| Tsunamis occur every year more than once. Significant tsunamis have occurred causing destruction and affecting coastal populations. Following table shows a few of them, 1929 Grand banks 1946 Aleutiah 1952 Kamchatka 1957 Aleutian 1960 chile 1964 Prince William Sound 1975 Howaii 1996 Peru 2004 Sumatra Wind generated waves on a sea beach, due to storm in the ocean, are periodic rolling waves of about few meters height, with wave length of 100 to 150 meters and 10 to 15 seconds time period. Tsunamis have wavelength of 100 km and time period of about 1 hour. As a tsunami approaches land, depth under shallow water forces the height of water to rise sharply. A large wall of water hits the beach with great ferocity as all the energy stored in the wave dissipates on land structures. Ships in deep waters of oceans during tsunami occurances are not disturbed more than few feet.A tsunami as it approaches land, it begins to slow and grow in height. Tsunamis reach the coast with almost all the energy, it started with. Recent Tsunamis showed tremendous erosional power, uprooting all the trees and other coastal vegetation, flooding kilmeters of beaches, crushing homes and almost all coastal structures. Recent Tsunamis reached vertical heights onshore above much more than 30 meters in many places. Sumatra lies on the fault region or plate boundaries where plates interact. Large vertical movements of the earth's crust occurs at plate boundaries. Recent Tsunamis were generated when the sea floor abruptly deformed and vertically displaced the water above the region. Tectonic earthquakes or earthquakes due to the earth's crustal deformation below the sea displaced water mass and formed tsunami waves. As large areas of the sea floor elevated or subsided, tsunamis were created. Following video clips demonstrate the tsunami ferocity. Movie (2 MB), Movie (2.3 MB), Movie (2.6 MB), Movie (6.2 MB) http://www.geophys.washington.edu/tsunami/movies/hokkaido1.mov http://www.geophys.washington.edu/tsunami/movies/globe.mov http://www.geophys.washington.edu/tsunami/movies/kanto1.mov http://www.geophys.washington.edu/tsunami/movies/kanto2.mov A Video clip showing the onslaught of Tsunami on Penang beach, Thailand (60 secs) |
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| Increasing wave height |
| Shallow waters |
| Tsunami waves shown in picture |
| Recent Tsunamis, Tsunami video clips |
| Video clips on Tsunami |
| Tsunami |
| Tsunami death toll 2004 over 280,000 |