something that probably did implode, if not in the SOFAR channel, then closer

to it.

In fact, you don't need to implode into the SOFAR channel because More or less, any sounds produced in the water column will be trapped by the SOFAR channel.

Oh, I see.

Because the SOFAR channel is more or less the seawater depth.

I mean, it goes from the surface down to 3,000 meters, about, depending on the latitude, of course.

So it's not a narrow layer, it's really the whole water column and then the waves.

Or as another example, acoustic expert I talked to indicated that, as you said, if there was something of sufficiently large volume inside the plane that would implode as it descended, that might create enough sound energy.