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Tsunami aboard yacht in American Samoa!
"thunder" wrote in message
t... On Sun, 04 Oct 2009 12:36:52 -0400, Wilbur Hubbard wrote: If you can feel and hear an earthquake on land it generally means it is probably within a couple hundred miles of you. (in this case it was about 150 miles away). Intelligence also means you know the typical tsunami travels about fifty miles per hour. I don't think that's accurate. Depending on the depth, a tsunami can travel @600 MPH. As the water gets shallower, the wave slows down. Perhaps you meant, 50 MPH when the wave had crested in the harbor. Wave speed is computed from the square root of the quantity water depth times the acceleration of gravity. The speed at which tsunamis travel depends on the ocean depth. A tsunami can exceed 500 mph in 15,000 feet of water but slows to 40 mph or less in 100 feet of water. In less than 24 hours a tsunami can cross the entire Pacific Ocean. Different types of tsunamis can definitely travel at different speeds depending on how they originate. The tsunami that struck American Samoa was caused by a shift in a fault line directly below the origin. This causes a slower wave train than if, for example, the side of a volcano sloughed off violently into the ocean. In this case the wave is hastened by the original push. I think the water around American Samoa atoll is quite shallow so it slows down the speed quite nicely. But, the point of origin is quite deep so that would have sped it up. But, you are right. I did underestimate the time factor. I should have called it an hour instead of three - still plenty of time for those losers to get out of there. Wilbur Hubbard |
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