A series of waves generated by an undersea disturbance like an earthquake, landslide, volcano or even meteorites is called a tsunami, pronounced "soo-nah-mee". The waves travel outwards from the disturbance in all directions like ripples in a pond. They can reach heights of more than 100 feet and can travel at an average of 450 mph. They appear normal as they approach the coastline and then grow to great height, smashing onto land and causing great destruction. Areas of greatest risk are less than 50 feet above see level and within one mile of shore.
Signs of an impending tsunami are:
Strong earthquakes offshore.
Rapid changes in water level is a sign of an approaching tsunami.
Successive series of "crests" and "troughs" (high and low water levels) 10-45 minutes apart increasing in size and intensity.
TSUNAMI FACTS
The 1964 Alaskan earthquake created a tsunami as far south as the California, Oregon and Washington coasts with wave 10-20 feet high.
Atlantic tsunamis are rare but the 1929 Grand Banks, Newfoundland earthquake caused a tsunami that devastated Placentia Bay, Newfoundland.
The 1946 tsunami that his Hilo, Hawaii hit with waves 20-32 feet. It flooded the downtown area and killed 159 people.
There are two tsunami warning centers - one in Honolulu, Hawaii and one in Palmer, Alaska. They monitor oceanographic disturbances that trigger tsunamis. They are responsible for tracking and issuing tsunami warnings.
More people have been killed since 1945 as a result of tsunamis than as a result of the earthquake or disturbances that caused them.
BEFORE A TSUNAMI
Find out if you're in a danger area. If you live on a coastline, contact your local emergency management office to determine your risks.
Know your elevation above sea level. Evacuation orders are usually based on that.
Familiarize yourself with the tsunami warning system.
Be aware of any offshore disturbances that may cause a tsunami or signal it's approach such as earthquakes, volcanic eruptions or the rapid rise and fall of coastal waters.
Have a Family Disaster Plan in place.
Know your evacuation routes.
Learn where and how to cut off electricity, gas and water in your home. Have the proper tool to do it.
Discuss tsunamis with your family.
DURING A TSUNAMI
Listen to the radio or television for updates and warnings.
If you hear the official warnings or notice the signs, evacuate IMMEDIATELY to higher ground. A tsunami warning means that the threat exists.
Stay away from the beach. If you can see the wave then you're too close to escape it.
Return home ONLY when the threat no longer exists and authorities have given the okay. Remember that a tsunami is a series of waves. The next wave may be stronger than the first one. Never assume the threat has passed.
AFTER A TSUNAMI
Follow emergency broadcasts for information.
Help emergency workers with trapped or injured victims. Give first aid where appropriate but NEVER move severely injured persons unless they are in further immediate danger. Call for help immediately.
Stay out of damaged building and return home only after the all-safe is given.
Use a flashlight and NEVER turn the electricity back on until the building has been inspected for downed wires and shorts.
Open windows and doors to help dry out the building.
Shovel out mud and debris while it is still wet to help dry out walls and floors.
Fresh food that has come in contact with floodwater may be contaminated. Also have your tap water lines tested for contamination due to breaks and leaks.
|
|
|
|
|
|
|
|
|
