A team of researchers from the Fujian Institute of Research on the Structure of Matter in China are suggesting that an ultra-sensitive magnetic detector could be used to track advanced U.S. submarines from long distances.

According to the team, detection of such stealthy submarines could potentially be achieved by detecting the nearly imperceptible bubbles produced as they travel through water. The researchers revealed that they have created a computer model demonstrating that this approach might work.

Source: Official U.S. Navy Page/CC BY 2.0

The success of this approach would rely on submarines not being able to avoid producing these bubbles as their motion causes the water surrounding the hull to move faster, thereby reducing its potential energy, which is expressed as pressure and as it decreases, some of the water vaporizes to keep the energy equilibrium.

This reportedly occurs in areas of sharp curvature or when surfaces are rough. As the water flows around the hull, the bubbles get larger and shift away from the surface, and the higher pressure encourages them to violently collapse. This produces a so-called electromagnetic signature called the magnetohydrodynamic (MHD) effect.

Using the computer modeling employed by the researchers, the electric field signals produced through this phenomenon can be detected around the bow, stern and rear of the hull. Further, the signals can be distinctly detected even in the low-frequency range of 49.94 Hz to 34.19 Hz.

Such faint signals, according to the researchers, can reportedly travel over long distances, penetrating the water and traveling to the ionosphere before being reflected back on Earth.

The researchers are detailing their findings in the Chinese Journal of Ship Research.