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Why is a 3.3 foot wave considered a tsunami?
From an AP story about the impending tsunami about to hit Japan...
"Japan's Meteorological Agency had said that waves as high as 3.3-feet could hit the northeastern coast of Japan's main island of Hokkaido around 2 p.m. (12 a.m. EST)"
Why is that such a big deal? Aren't double overhead surf waves a lot taller than 3.3 feet?
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