Tsunami warnings

@Magus274 (664)
New Zealand
March 4, 2010 7:14pm CST
Why is it that civil defence warnings about tsunami are either 1. Too late and 2. blown out of proportion. I would think it would be easy to monitor a sizeable wave/s from the air, and then transmit information to threatened coastlines. Rather than judge by the size of the earthquake to determine the threat while being stuck behind a computer desk. I'm interested if anyone has any ideas on this subject.
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