[dr_lew]

“You’re displacing a huge mass, which must generate movement of water,”

There's science for you ... "huge". Huge like a Stag Beetle? a galaxy? an ocean liner?

To me the relevant parameters are radius and amplitude. As a first guess, we might think that the height, or amplitude, of the wave might be a measure of its energy per unit length, on the basis of gravitational potential energy.

So this will diminish in proportion to the distance from the source. That leaves the question of how to evaluate the amplitude of a point source, which will diminish very quickly with distance. Perhaps there is some effective radius on the order of the width of the wave.

Generously supposing this radius to be 1 km, then we would expect the wave amplitude to be 1/100 the size of the Chrysler building at a distance of 100 km. And so on.

That's still a big wave!

[Teacher317]

Plenty of things fall into the ocean without creating waves of significant size. The ocean is pretty big. The mass entering the water does not automatically create waves of the same mass.

Big rocks move over long periods of time thanks to gravity, tectonics, human activity, etc. Color me very skeptical.

[chris37]

There was a program a number of years ago on Nat Geo I believe that demonstrated how large chunks of vertical cliff breaking away and thus becoming high speed landslides can displace a huge amount of water.

They displace much more water than just the mass of the land itself, because of the speed at which the land falls into the water apparently also pulls air into the space where the water was very quickly.

They demonstrated this effect in a small scale tsunami tank in some university.

They then theorized that this explained how some fossils unique to the area of Hawaii were found at the top of some Australian mountains some 600ft up if I recall correctly.

But their general hypothesis was that high speed landslides are capable of creating massive waves that move at a high rate of speed and do not lose energy over very long distances.

[alancarp]

While I’m hardly an expert, that result is a lot closer to what I’d expect based on the raw physics.

When energy starts as a central source and radiates outward, the energy is spread out proportionately... it does not amplify, for that’s impossible without more energy.

This is why tsunami forecasts are lower for more distant target zones...anybody who says this event would be different is simply hyping disaster shows (looking at you, Discovery Channel).