Do not go near the shore to watch a tsunami hit. If you can see it, you are too close to escape. Should a tsunami occur and you cannot get to higher ground, stay inside where you are protected from the water. It's best to be on the landward side of the house, away from windows.
Tsunamis are detected by open-ocean buoys and coastal tide gauges, which report information to stations within the region. Tide stations measure minute changes in sea level, and seismograph stations record earthquake activity.
Warning criteria
That warning, he says, can go out within three to five minutes of the undersea earthquake and gives an early indication of its potential to cause a tsunami which may do damage. "If the earthquake is big it could be moving quite a lot of sea floor — often along a subduction zone", he explains.Experts believe that a receding ocean may give people as much as five minutes' warning to evacuate the area. Remember that a tsunami is a series of waves and that the first wave may not be the most dangerous. The danger from a tsunami can last for several hours after the arrival of the first wave.
Tsunamis are a series of very dangerous, large, long ocean waves. Since 1946, more than 220 people have died in the State of Hawaii, including six on Oahu, due to tsunamis.
Tsunami Warning – A tsunami warning is issued when a tsunami with the potential to generate widespread inundation is imminent, expected, or occurring. Warnings alert the public that dangerous coastal flooding accompanied by powerful currents is possible and may continue for several hours after initial arrival.
Tsunami are waves caused by sudden movement of the ocean surface due to earthquakes, landslides on the sea floor, land slumping into the ocean, large volcanic eruptions or meteorite impact in the ocean.
In some places a tsunami may cause the sea to rise vertically only a few inches or feet. In other places tsunamis have been known to surge vertically as high as 100 feet (30 meters). Most tsunamis cause the sea to rise no more than 10 feet (3 meters).
Large tsunamis have occurred in the United States and will undoubtedly occur again. The tsunami generated by the 1964 magnitude 9.2 earthquake in the Gulf of Alaska (Prince William Sound) caused damage and loss of life across the Pacific, including Alaska, Hawaii, California, Oregon, and Washington.
Most people do not survive being swept into a tsunami. But there are a few ways you can protect yourself from these natural disasters. Your exact strategy will depend on where you are, and will go a lot more smoothly if you have planned in advance.
Boxing Day tsunami in 2004
ANSWER: The area with loosely compacted soil is most likely to be the safest during a major earthquake.
3.5 How long does a tsunami last? Large tsunamis may continue for days in some locations, reaching their peak often a couple of hours after arrival and gradually tapering off after that. The time between tsunami crests (the tsunami's period) ranges from approximately five minutes to two hours.
