November 28, 2017

Wide Search Area for San Juan May Take Months/Years


The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has advised that its hydrophones point to an extensive ellipse shaped search area, that is 100 to 200 km wide, off the Argentine coast. If CTBTO was the only hydrophone owner "100 to 200 km wide" would be bad news as such an area might take months or years to effectively search.

The explosion/implosion may have resulted in small rusting fragments, collecting barnacles and seaweed, that becomes steadily harder to "image" as a submarine. 

Much depends on the US Navy, and maybe others, having hydrophones and other sensors closer to the action - that can privately point to a much smaller, hence more useful, search area. 


Gleaned from Davide Castelvecchi's report of 27 November 2017 for Nature magazine. According to CTBTO six of its underwater stations are equipped with hydrophones. Two stations picked up the alleged San Juan signal (see Map 1. below), including: 
-  one station at Ascension Island, slightly south of the equator in the Atlantic, and 
-  the other in the Crozet Islands in the Southern Indian Ocean, half-way between Africa and 

These two stations saw the same signal. So an approximate 100 to 200 kms wide search area can be deduced. 
Map 1. CTBTO's hydrophones on 15 November 2017 detected what is considered San Juan's explosion/implosion where the blue lines cross. However these CTBTO detection points are very distant from San Juan, yielding the 200 km wide ellipse in red
The fact that the sound was detected with a good signal-to-noise ratio at Ascension and also at Crozet - 6,000 to 8,000 kilometres away from the source - means the source of the noise was loud (like an explosion/implosion).

Map 2. - The ellipse closer up - presenting a wide search area, with the additional problem of three dimentional depth. CTBTO is still assessing the margin of error in its hydrophone "localisation". 

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