Originally Posted by
wdew
Wonder then why they didnt pick it up when MH370 hit the water eventually...?
As you perhaps know, the CTBTO sensors did pick up an acoustic event of interest:
Curtin University researchers have been examining a low-frequency underwater sound signal that could have resulted from Malaysian Airlines Flight MH370.
The signal, which was picked up by underwater sound recorders off Rottnest Island just after 1:30 am UTC on the 8th March, could have resulted from Flight MH370 crashing into the Indian Ocean but could also have originated from a natural event, such as a small earth tremor.
However, there are large uncertainties in the estimate and it appears it is not compatible with the satellite ‘handshake’ data transmitted from the aircraft, which is currently considered the most reliable source of information.
Scientists from Curtin’s Centre for Marine Science and Technology along with colleagues from the United Nations’ Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) and Geoscience Australia have been involved in the search for sounds that might help with search efforts.
Curtin researchers in search for acoustic evidence of MH370 - News and Events | Curtin University, Perth, Western Australia
Further analysis determined that the event was probably a false lead:
The Australian team was able to confirm their finding with help from another organization interested in undersea acoustic anomalies, the Comprehensive Nuclear-Test-Ban Treaty Organization, which operates a global network of seismic detectors and other instruments designed to hunt illegal underwater nuke testing. Unlike the Curtin team's equipment, the "CTBTO's stations have two sets of three hydrophones separated by several kilometres, which—like a pair of human ears—allow listeners to get a fix on a sound's direction to within 0.5 degrees," according to a post at nature.com.
The anomalous signal first discovered in June now appears to be a false lead, according to an update in Nature. With help from additional data collected at a different sensor, it now seems much more likely that the crashing sound was geologic in origin. The signal probably originated somewhere along the Carlberg Ridge, which extends from near the Horn of Africa northeast almost to India. Rather than an airliner impacting the ocean surface, the sound was more likely "caused by an earthquake, underwater landslide, or volcanic eruption," Duncan told nature.com last week, effectively confirming the signal as a dead-end.
https://motherboard.vice.com/en_us/a...n-more-missing
Kinda reminds me of the Vela satellite double flash incident in 1979 which at the time was deemed publically to be a false alert:
https://en.wikipedia.org/wiki/Vela_Incident
Anyway, with the current missing sub there is probably closely held acoustic data from SOSUS arrays and undersea platforms that may be shared discreetly to aid in the search and investigation.