What is Tsunami
- Tsunami is a Japanese word. "Tsu" translates to harbor, and "nami" to wave. When a body of water is rapidly displaced, a series of waves are created. These series of waves are called a "tsunami". These waves are usually 10 meters high.
- A tsunami caused by an underwater earthquake, landslide, or volcanic eruption. More rarely, a tsunami can be generated by a giant meteor impact with the ocean.
- A tsunami is not just one wave but a series of waves or a “wave train.”
- Many witnesses say a tsunami sounds like a freight train.
- Tsunami waves can be as long as 60 miles and be as far as an hour apart. These waves can cross entire oceans without losing much energy.
- Scientists can accurately estimate the time when a tsunami will arrive almost anywhere around the world based on calculations using the depth of the water, distances from one place to another, and the time that the earthquake or other event occurred.
- Hawaii is the U.S. state at greatest risk for a tsunami – they get about one per year and a damaging one every seven years.
- In 2004, the Indian Ocean tsunami was caused by an earthquake that is thought to have had the energy of 23,000 atomic bombs. Within hours of the earthquake in 2004, killer waves radiating from the epicenter slammed into the coastline of 11 countries, damaging countries from east Africa to Thailand. By the end of the day, the tsunami had already killed 150,000 people. The final death toll was 283,000.
Warning Signs
- An earthquake is a natural tsunami warning. If you feel a strong quake do not stay in a place where you are exposed to a tsunami. If you hear of an earthquake be aware of the possibility of a tsunami and listen to the radio or television for additional information. Remember that an earthquake can trigger killer waves thousands of miles across the ocean many hours after the event generated a tsunami.
- Witnesses have reported that an approaching tsunami is sometimes preceded by a noticeable fall or rise in the water level. If you see the ocean receding unusually rapidly or far it's a good sign that a big wave is on its way. Go to high ground immediately.
- Many people were killed by the Indian Ocean tsunami because they went down to the beach to view the retreating ocean exposing the seafloor. Apparently they were unaware that this phenomenon precedes a killer wave. Experts believe that a receding ocean may give people as much as five minutes' warning to evacuate the area.
- Because tsunamis can approach the shore as fast as 100 miles per hour (160 kilometers per hour) it is often too late to get away if you see one. An approaching tsunami is not something to be admired unless you are safely on high ground.
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