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Everything you need to know about tsunamis in Hawaii.

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After the devastating and highly publicized tsunamis that took place in 2004 in the Indian Ocean and in 2011 in Japan, most of us have a rough idea of what a tsunami is. For those that are still confused, it's basically a long and tall sea wave caused by a disturbance like an earthquake or submarine landslide. It comes from the Japanese words "tsu" which means harbor and "nami" which means wave.

The Dangers

The obvious dangers of tsunamis are the enormous amount of water they bring along with a huge amount of force that comes with that water. What many don't realize is that a tsunami can travel thousands of miles from where they were generated.

Now, take a set of tiny Hawaiian Islands and plop them down into the middle of the Pacific Ocean without any land barriers to protect them. Surround them with the infamous Ring of Fire where a large number of earthquakes occur and you have a recipe for potential disaster.

An earthquake near Japan can send tsunamis waves east towards Hawaii. A large California quake could send tsunami waves to the west towards the islands. A quake or massive landslide, which many experts say is overdue, near Chile could spell disaster for these tiny rocks we call the Hawaiian Islands. Even Alaska has the potential to do us in.

Are we over-worried? Of course not, we know what these things can do when they hit land. They run across thousands of miles of open ocean with nothing stopping them. As they approach land a massive wall of water forms that can be well over 100 feet tall (the Japan tsunami in 2011 was estimated to be 128 feet tall). They can quickly kill tens of thousands of people, destroy million of homes and structures, and cause billions in damage ($235 billion is the estimate in Japan).

Tsunamis In Hawaii's History

Has a tsunami ever hit Hawaii? Yes! And it will certainly happen again, we just don't know when. The most notable tsunami in Hawaii's history happened on April 1, 1946 (yes, April Fool's Day but this is no joke). It was caused by a magnitude 8.6 earthquake near the Aleutian Islands in Alaska.

The quake caused the seafloor to rise and when that happens the water gets displaced and rushes outwards. As it sped across the ocean it approached the Hawaiian Islands almost 5 hours later and the waves raised up and generated massive waves that struck various parts of the islands. One of the places that got hit the worst was Hilo on the Big Island which saw a lot of destruction and loss of life. The Pacific Tsunami Museum exists today as both a reminder of the events of April 1, 29146 and as a place of tsunami education.

Tsunami Avoidance

Believe it or not, some good came out of the 1946 tsunami that killed so many and destroyed so much. That good was the creation of the Seismic Sea Wave Warning System which today we know as the Pacific Tsunami Warning Center. The best way to handle a tsunami is with information that one may be coming. You can't stop it, you can't slow it down, all you can do is get out of its way and the Pacific Tsunami Warning Center gives people all around the Pacific a chance to get out of the way.

On top of that, the islands have a large array of tsunami warning sirens places in strategic spots (those vulnerable to tsunami waves). If the Pacific Tsunami Warning Center tells the local government that a tsunami is coming you'll hear those sirens blaring. Note that the sirens are tested each month via a 45 second long test on the first workday of each month at 11:45 AM.

Fortunately, the upside to many tsunamis are that they take hours to reach the islands. This gives you a chance to prepare for it by getting to higher ground. Be sure to read all about Emergency Preparedness so you can grab your bug out bag and go if you hear the tsunami sirens going off.

The important thing in a tsunami is height so get away from lower land near sea level and get elevated, which usually means driving inland to a higher elevation. Never go near beaches or waterways when a tsunami watch or warning has been issued.

Keep these tsunami resources handy:
Pacific Tsunami Warning Center Website
U.S. Tsunami Warning Centers
Tsunami Evacuation Zones & Maps
Hawaii Emergency Management Agency