Anyone expecting to travel to, or live by the Pacific Ocean must be aware of the effects of tsunamis. Education in the characteristics of tsunamis, as well as the disastrous results when these ocean waves come ashore, will increase chances of survival.
A tsunami is a wave series that speeds over the open ocean at very high speeds, up to six hundred miles per hour, before making landfall. Tsunamis are created by earthquakes and volcanoes, and take their name from the Japanese. Translated to English, it is "harbor wave". A tsunami is actually a ripple effect, much like dropping a stone into water and seeing the waves travel out from the source in all directions. They are hundreds of miles long, have a relatively low profile, and are virtually undetected by passing ships.
When the waves get closer to a land mass, they slow down to approximately thirty-five miles per hour, and grow taller in height as the waves climb up with the rise of the ocean floor. If the rise of the seafloor is steep, the wave will be dramatic in height. The approach can be seen as changes between high and low water levels at the shore, in intervals of ten to forty-five minutes. A local tsunami can have effect in less than ten minutes, which is not enough time to issue a warning.
Major earthquakes have given reason to suspect the generation of tsunami, and the following would be issued:
- Tsunami information bulletin = a threat exists.
- Tsunami watch = residents should be alert.
- Tsunami warning = tsunami arrival times are given
Those at risk would be within one mile of the coast and less than 25 feet above sea level. A tsunami will arrive as a series of waves, so there is danger even after the arrival of the first wave. They also "wrap around" an island, carrying debris as they go, and the waves can vary in their intensity, with the following waves causing more havoc that the first.
To survive a tsunami event, please pay attention to the following:
- If you feel an earthquake, expect a tsunami warning in its wake, and vacate low-lying areas.
- If you see a drop in sea level; leave the area immediately. Also, a tsunami may sound like an oncoming train.
- A tsunami can also be dangerous farther from shore because it can carry buildings, cars, and boulders as it travels.
- Do not go to the shore after a warning has issued to go on a tsunami "hunt". You may not be able to get away quickly: If you can see it, you will not be able to outrun it.
- Do not mix a tsunami with sports. A tsunami cannot be surfed; the wave does not curl and break for surfing.
- Most deaths occur from drowning. Being wary of any abnormalities due to earthquake activity will help you survive a disaster caused by a tsunami.