Summary: if you're not looking for transients, you may be missing
the "boat."

Much of what follows has previously been addressed on this site
but an apparent lack of action suggests a repeat may be useful.

About 10 years ago, I discussed the reported PACSOSUS
detection of the loss of the Soviet GOLF Class SSB K-129
on 11 March 1968 with then-LTJG John Olney who had
been a member of the PACSOSUS analysis team who
identified the detection.

What Olney described to me was so appalling that – without
any comment, I forwarded his description to George Miller,
then retired after tours at PacBeach, SanNic and Adak, and
30 years at STIC/ONI.

George's response: “You wouldn't have sent that to me unless
you thought it was the Bonin Island Volcanoes.” – and so it
was.

About the same time, I received AFTAAC data on the actual
detection of the K-129 event. CNO had confiscated those data
in 1968 and never gave it to NAVSTIC as we were known then.

That relatively easy analysis – took only few hours – identified
three battery-generated hydrogen explosions that had killed the K-129
crew who were thus unable to stop a missile launch training event
scheduled for 12:00:00 GMT from becoming the firing of two R21/D4
missiles to fuel exhaustion in their closed launch tubes causing the loss of
the K-129: burned all the way through the keel area.

That K-129 acoustic data had been detected. by the AFTAAC hydrophone
at Midway Island at a range of about 700nm. The signal excess at
that range indicated many (most?) of the signals probably were detected
by all West Coast arrays. In fact, other AFTAAC single phones had detected
some K-129 events at ranges as great as 2000nm

So why were they missed by PACSOSUS? Simple answer: they were transient
events not recognizably displayed by then operational displays. The three
hydrogen explosion signals had durations of 1.5, 2.4 and 0.7 seconds while
of the most detectable failed missile launch events had durations of less than
5.5 seconds.

So, that was 1968 – 51 years ago – what are we missing in 2019 by
not processing IUSS data for transient events of similar duration?
Answer; possibly a lot.

High on that list would be transients associated with BOREY and
YASEN Class submarines operating at speeds below 10 knots if
they use the turbo-electric mode of their hybrid propulsion system
which requires that the main turbine and gear system still be kept in
a “warm state,” ready for immediate use.
.
As previously discussed on this site, turning such propulsion
components over at very low speeds (to keep them ready for use)
can produce intermittent high levels of transient acoustic energy as
rotating shafts and gear wheels transiently “grab” (stop) transferring
impact shock to the entire power train. Such energy is difficult to
abate with standard noise reduction techniques.

Such transients have the potential to be more exploitable than
“standard” signals from such classes as the BOREY and YASEN..

Bottom line: you never know what you're missing until you look
by screening data with time resolutions of one second or less.
Good hunting.

Bruce, even among the best analysts I was ever associated with there was a tendency of some to have “analytical bias”; influence by the availability of a known candidate or known event. The very best usually didn’t need a candidate but would still be hard pressed real time to recognize events such as those associated with the Golf and other similar disasters, without prior knowledge it had occurred. Prior knowledge and perhaps recognizing an event as something one has seen before go a long way towards acoustic assessments. I was always impressed with some of the data generated by STIC/NISC but it tended to fall into the after-the-fact category, of course. More heroic were the very best Navy analysts making superb calls on a real time basis, in my opinion. They couldn’t tell you anything in milli-second values but could sure put a plane on top of a bad guy nobody knew about.

Randy:

I agree with you 100 percent; however, PACSOSUS was told when and generally where to look. Further, the
Bonin Islands signal had been around since the first PAC arrays went operational years earlier. The signal
sometimes went on for weeks.

Bruce

Bruce, that sheds different light on things, thanks. I did only one PAC tour and never could get used to a line of bearing going from right to left :)

Randy:

One of the reasons George Miller requested Adak - where he was OPS - was to get a
cut-off bearing for the Bonin Island source.

All the West Coast sensor bearings were close to parallel: trans-Pacific

Like the famous Mar 1991 source at 54.1S, 140.5W, the Bonin Island ramping signals
were (are) produced by changing relative water/gas volumes in black-smoker tubes:
giant pipe-organ/coke-bottle effects.

Assume the Bonin Islands are still - acoustically - a going concern. There was a ship
report of boiling water and mud in the area in 1907. Undersea volcanic activity can be
a very long-term business.

Curious if anyone of this site can provide a recent report of continuing activity.

Bruce

Certainly agree that parallel bearings were an issue. Not related to that, one of my best memories of CVB was getting to talk virtually real time with a P3. There was a dynamic and quickly changing event taking place and as I recall our secure
voice got connected to the ASWOC, who were on a secure system with the plane. We would share what was taking place and they immediately passed it on the P3. It was actually pretty effective. (I guess it helped that we had plenty of experience having new Ensigns talking to to planes and submarines through the DAC center, lol).

Randy:

Thank you for a wonderful story.

The date of that event wasn't Jan 1968 (X-5) was it?

Best,

Bruce

That probably would have been fall 1978.
I hesitate to give specifics but it involved a C2.
Lit us up pretty good!