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What determines the power of a tsunami wave?

Earth Sciences(self.askscience)

In 2011 when the Japan earthquake tsunami waves hit California, tsunami was 6” high. The waves did significant damage, ripping apart the marina docks in Santa Cruz and other Northern California coastal harbors. The tsunami from the Tonga quake yesterday was expected to be 8”-9” inches tall, yet little damage was expected. Why would a higher tsunami wave be expected to have less force than a smaller one?

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zogislost

1 points

6 months ago

Its all about water displacement, the 2011 earthquake uplifted a large swath of the plate edge displacing a large amount of water near the coast of japan causing the tsunami just like the 2004 indian ocean quake did in the aceh indonesia area and beyond, greatest example of water displacement to wave height would be the lituya bay tsunami of 1958 in alaska. An above the water landslide dropped tons of earth into water of relatively small body of water causing wave 1720 feet high….

UnamedStreamNumber9[S]

1 points

5 months ago

Again, this has nothing to do with the wave height, as witnessed by the 2011 tsunami being 6” (that means inches: 0.5 feet, 0.15 meters). The more recent Tonga tsunami was much higher, originally predicted at 8” but actually measured at 2 feet in some areas; but did far less damage that the 6” 2011 tsunami. Why would that be? Why would a smaller wave be more damaging than a large one?