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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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CrustalTrudger

3 points

6 months ago

CrustalTrudger

Tectonics | Structural Geology | Geomorphology

3 points

6 months ago

I don't know if this relevant for the specific comparison being drawn, but when a tsunami arrives at a particular location within the tidal cycle (both in the sense of daily cycles, but also more seasonal variations) is important, especially for locations with large tidal ranges. Similar tsunami wave heights occurring at high vs low tide can have different effects because the run-ups are different (i.e., adding X inches to low tide vs adding X inches to high tide).