That's what I was looking for, hydrophone networks picking up anything. The sharp violent 'explosion' I'm betting is the sub passing crush depth and then finally imploding; the incredible amount of pressure at those depths was enough to (in USS Scorpion's case) rip the sub literally in half and shove the engine room fifty feet forward into the hull behind the torpedo room. Very likely the same happened here, after some sort of catastrophic electrical casualty to the boat followed by a loss of power and a trip straight down.
Thank god the end came quick, is all I'm going to say.
What I said before about the SOSUS hydrophones (and NOAA's), those things are serious business. When Thresher went down, their recordings were good enough to hear the sound of water hitting the reactor core of the sub despite it being half an ocean away. That they didn't hear the sound let them rule out a failure there, so the listening capabilities of the USN (and others) are terrifying. Don't fart in the ocean, they'll know you did it.
