The nuke would do more damage on land than it would by causing a tsunami.
I’m not arguing the point, but wouldn’t you need a boatload of nukes to mimic a decent tsunami? Anyway, just read the article and think ‘force multiplier’.
Well, a tsunami is already a twofold indirect damager. earthquake or landslide -> displaced water -> tidal wave
A nuke would be better suited to causing a landslide, though it would require the necessary unstable feature in the appropriate location. Attempting to use a nuke in place of an earthquake instead would require significantly more energy in for the amount you'd get out. In the case of the instigated landslide, you're taking advantage of an already existing massive source of energy, far greater than that of the nuke you're going to unleash it with. (getting a few cubic miles of material to shift hundreds of feet under tons of water is very
energetic) That's one kind of "force multiplier".
The tsunami itself is an interesting "apparent force multiplier" itself. There's an "amplification effect" with tsunamis. It's not a real amplification but it certainly has the appearance. When a landslide happens a few miles below the surface, it may only cause a wave a few inches to a few feet on the surface. But remember, that's lifting a column of water that's miles high, it's an enormous
mass to be lifting, even if only a few feet. It embodies a huge amount of energy.
When that wave travels, as it approaches land, the column height is shorter and shorter. The energy remains the same. (waves are very efficient at transmitting energy in water) So the wave gets higher. This keeps up until it hits land. That's why you can start with a wave a few feet high and a few dozen feet across in the middle of the ocean and end up with a 25 foot tall wall of water for a mile back by the time it hits landfall.
Experienced sailors can sometimes recognize these "rogue waves" as tsunamis, and that's the basis of the tsunami warning systems, they're floats that measure small coordinated waves to help identify tsunamis and provide advance warning. (often an hour or more) Imagine being able to predict a tornado or an earthquake an hour before it gets to you.
Though one quality of a tsunami that's impossible to appreciate without watching the video is the [i]withdrawl[i] phase. All that water comes in, maybe 3-5 ft high, but may got a mile inland. It's actually accounts for a small percentage of the end damage that's going to be caused. Once inland, it breaks up stuff, floats and picks up debris, and then it heads back out to sea. This debris is effectively a mudslide, and can do a lot more damage, break up a lot more stuff to increase its volume, and easily take someone that was floating harmlessly in the water miles out to sea to drown. (making matters worse, there's often more than one of them, it's a bit like aftershocks for an earthquake, so just when you're rushing in to try to help after the withdrawal, another one comes in)https://www.youtube.com/watch?v=TRDpTEjumdo
then check out the wave that comes in at 4:50... just when you thought you had a lot of water coming in, you see THAT wave curling in!https://www.youtube.com/watch?v=IAa8BmuPqh8
dry to raging river in 90 seconds... the speed at which these things develop just defies belief.https://www.youtube.com/watch?v=IAa8BmuPqh8