American sailors could have obtained the acoustic signature (a term used to describe the combination of acoustic emissions from sound emitters, including ships and submarines) of the Russian 4th generation multi-purpose nuclear submarine K-561 "Kazan" (the second ship of Project 885M "Yasen-M") during its stay in Havana. This is reported by Bulgarian Military.
According to the publication, the US uses effective methods to detect Russian submarines in the Atlantic. Several detection systems are deployed in the Barents and Norwegian Seas, as well as in the Faroe-Iceland Passage and the Davis Strait.
American anti-submarine forces have advanced systems for detecting enemy submarines. So it is almost impossible that the "Kazan" nuclear submarine crossed the Atlantic unnoticed.
Methods for Detecting Enemy Submarines
Submarines can be detected by acoustic methods (a non-destructive testing method based on the use of elastic waves, i.e., vibrations occurring in the object under control). The first method is passive direction finding. The second method is active sonar.
Stationary hydroacoustic reconnaissance systems and surface ships use both passive and active hydroacoustic methods.
Russian submarines have a low noise level, making them very difficult to detect. But if sailors have an acoustic signature, the so-called "profile" of a specific submarine, it will help to separate background noise from its noise.
It is possible that American sailors recorded the acoustic profile of "Kazan". Now they will be able to isolate certain acoustic "pieces" belonging specifically to this submarine and add them to the acoustic signature database.
About the "Kazan" Submarine
The "Kazan" nuclear submarine is a multi-purpose nuclear submarine built according to Project 885M by the Malakhit Design Bureau at the Sevmash plant. The submarine is part of the Northern Fleet.
"Kazan" is equipped with high-precision long-range missile weapons. It can effectively engage targets both on land, on the surface, and underwater.
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