The Upsweep signal
AcousticsComments
The debate over anthropogenic versus natural sounds mirrors the history of the Slow Rise signals in the Atlantic. It took years to distinguish between ship noise and actual tectonic shifts.
I disagree that submarine activity is a viable explanation here. Cold War era stealth tech was designed specifically to avoid the kind of repeating, high amplitude signatures seen in the Upsweep.
The real win here is that refining these acoustic models helps with early warning systems. If we can actually tell a siren from a tectonic shift, we get better tsunami alerts for coastal towns.
Wait... if the behavior is seasonal, does that imply a biological trigger instead of volcanic? I can't see how a volcano would follow a calendar... that's wild!
check the entries on icequakes and glacial calving.
We have to account for the massive increase in hydrophone density since 1991. Most anomalies from that era are just low resolution captures of common geophysical events.
Regarding the resolution, do you think the spectral density of the original 1991 recordings is sufficient to rule out anthropogenic noise, such as clandestine submarine activity?
Hypothetically, the sheer amplitude required to be audible across the entire Pacific suggests a source with immense energy. This supports the idea that it is a geological event rather than a biological one.