Tsunami’s are Ocean Waves produced by earthquakes occurring under the ocean. The word tsunami originated in Japan because of the large amount of tsunamis that have devastated Japan’s coastline. On the open ocean, tsunamis cannot be felt by ships because the wavelength would be hundreds of miles long, with an amplitude of only a few feet. This means that you can only see the tsunami as it approaches land because the waves start to bunch up in the shallowing water and the only place the water has to go it up. That means that detecting tsunamis at sea or from the air is impossible until its too late. Unusual wave heights have been known to be over 100 feet high. However, waves that are 10 to 20 feet high can be very destructive ( as in the Indian Ocean Tsunami) and cause many deaths or injuries.

 Tsunamis are mainly generated by earthquake-induced movement on the ocean floor. Landslides, volcanic eruptions, and even meteorites can also generate tsunamis. If a major earthquake happens near a costal area, a tsunami could reach the beach in a few minutes, even before a warning is issued. Areas at greatest risk are less than 25 feet above sea level and within one mile of the shoreline. Most deaths caused by a tsunami are because of drowning.
From an initial tsunami generating source area, waves travel outward in all directions like the ripples caused by throwing a rock into a pond. As these waves approach coastal areas, the time between successive waves can vary from 5 to 90 minutes. The first wave is usually not the largest in the series of waves, but can be. Tsunamis can also travel up to 2 miles up rivers and large streams inland. Many people think that there are specific tsunami danger zones but tsunamis can strike any coastal area.