Surf's Up
If you have ever been to the beach, chances are you have seen a particular animal called a "surferpod." Just kidding. There is no such animal, but there are plenty of surfers waiting for just the right wave to ride.
Surfing is a lot of fun when the rules of water safety are observed. Surfers sometimes go all over the world in search of the biggest waves.
Surfers know about a special kind of wave that is very destructive and can cause injury and death. You may have heard of them too. They are called tsunamis (pronounced soo-nah-meez).
A tsunami is actually a series of giant waves. Tsunami is a Japanese word that means "harbor wave." Tsunamis are caused by seismic forces, like underwater earthquakes and landslides, or volcanic eruptions. In an earthquake or landslide, the sea floor is displaced or broken by a huge crack. When this happens, the water rushes into the new crack. This causes the sea to bulge at that point and a series of waves begin.
Tsunamis appear to be a huge version of the regular waves we see at the beach. Normal waves last about 10 seconds and have a wavelength of 150 meters. By comparison, a tsunami wave can last up to one hour and can have a wavelength of 100,000 meters!
Out in deep water these waves pick up speed and intensity. Experts have estimated that in deep water these waves may reach speeds of over 500 miles per hour (as fast as a plane) and reach heights of more than 100 feet which is about as tall as a seven story building!
Tsunamis don't pose a threat for those who live inland and they are pretty rare. However, coastal communities must be prepared for tsumanis just like any other natural disaster.
Tsunami Safety
Here are just a few safety tips from FEMA (Federal Emergency Management Agency):
- Find out if your home is in a danger area.
- Know how far above sea level you live, and find out the distance between your home and the coast.
- Be familiar with the tsunami warning signs. Because tsunamis are caused by underwater disturbances or earthquakes, people living along the coast should consider an earthquake or a sizable ground rumbling as a warning signal.
- A noticeable rapid rise or fall in coastal waters is also a sign that a tsunami is approaching.
- When you hear a tsunami warning, move at once to higher ground and stay there until local authorities say it is safe to return home.
- Make sure all family members know how to respond to a tsunami.
- Have an evacuation plan with more than one escape route in case roads become blocked.
- As in all emergency situations, be prepared!
Related Websites
If you'd like more information on tsunamis, surf these cool websites:
Websites:
FEMA (Federal Emergency Management Agency) has a wonderful kids site at:
http://www.fema.gov/
The Western States Seismic Policy Council has interesting tsunami information at:
http://vishnu.glg.nau.edu/wsspc/tsunami/TsunamiHMC.html