Why are there no actual videos of any hundreds of feet high tsunamis?

Question

Any tsunami video I look at barely looks like a 20 feet wave hitting shore. But wikipedia tells me there have been dozens of 100+ feet tsunamis even in the last 10 years.

In: 1276

Answer 1

First off, the height of a wave cannot exceed the water’s depth. So a 100ft wave needs to be in at least 100ft water depth. Realistically, a 100ft wave would need around 135ft water depth.

Second, some tsunami height measurements are actually the [wave runup](http://www.coastalwiki.org/wiki/Wave_run-up), which is the maximum elevation that the water reaches on land, and not the actually height to the wave crest.