Natural and Man-Made Disasters
How frequently have tsunamis occurred throughout the world?
Tsunamis typically occur about every six years in the Pacific Ocean, and most often during March, August, and November. Although sometimes called tidal waves, tsunamis are created not by tides but by seismic movements (earthquakes), which produce chains of waves that move across the water at terrific speeds of more than 500 miles per hour. Upon reaching shallow water, the waves grow in height, sometimes to 100 feet or more, as was the case in 1883 when tsunamis reaching up to 130 feet hit an Indonesian island, destroying more than 150 villages and claiming some 36,000 lives.
In ancient times, it is believed that a tsunami destroyed the Minoan Greek culture, that of a people who lived on the island of Crete (in the Mediterranean Sea). In about 1450 B.C. Crete was struck by a 200-foot tsunami, which either demolished the island or weakened the population such that they could be taken over by the Mycenaeans, who were Greek mainlanders.
While tsunamis are known to strike along the Pacific Rim, damage has been minimized by sophisticated instruments that help meteorologists monitor and predict disastrous weather, alerting the public to evacuate from areas of possible danger. Such systems did not exist for the Indian Ocean when a 9.0 earthquake off the coast of the Indonesian island of Sumatra struck on December 26, 2004.