Chinese researchers find novel method to track US submarines

Known for their stealth, US submarines could lose their advantage after further research in this area.
Ameya Paleja
Stock image of a US submarine
Stock image of a US submarine


Researchers at the Fujian Institute of Research on the Structure of Matter in China have found that an ultra-sensitive magnetic detector could be enough to track down the most advanced of US submarines even from long distances, the South China Morning Post reported. The researchers published their findings in the Chinese Journal of Ship Research, a publication with a strong track record of cutting-edge reports in ship and ocean engineering.

In the recent past, the US and China have engaged in a race in various technological areas ranging from hypersonic weapons to spacecraft. There is plenty of evidence to suggest that the US has been slagging in these important technological areas of the future. However, in military technology, the US retained its lead in advanced aircraft and difficult-to-detect submarines.

The latter could be the latest frontier to collapse after Chinese researchers have found a new way to detect the most advanced of US submarines and take away their advantage of stealth altogether.

How China could spot US submarines

The US already uses multiple methods to minimize the detection of its submarines from advanced technologies. However, the approach of the Chinese plan could be extremely difficult to avoid.

Researcher Zou Shengnan and her team were looking at the possibility of detecting almost imperceptible bubbles made by the submarine as it cruises through water and has now successfully generated a computer model to demonstrate that it could potentially work.

Submarines cannot avoid these bubbles as their motion causes the water around the hull to move faster, reducing its potential energy. The potential energy is expressed as pressure and as it decreases, some of the water vaporizes to maintain the energy equilibrium.

This process occurs more in areas of sharp curvature or where the surface is rough, and as water flows around the hull, the bubbles get bigger and move away from the surface. Here the higher pressure causes them to collapse violently, resulting in an electromagnetic signature, a phenomenon known as the magnetohydrodynamic (MHD) effect.

Chinese researchers find novel method to track US submarines
Small bubbles arising from the submarine's movement in the water

Making a submarine detector

According to the computer modeling done by the researchers, the electric field signals can be observed around the bow, stern, and rear of the hull, and the distinct signals can be detected in the extremely low-frequency range of 49.94 Hz to 34.19 Hz.

These might sound like extremely faint signals, but they are capable of traveling over large distances since they can penetrate the water and travel to the ionosphere before getting reflected back on Earth. Submarines already use these waves for communication and have sensors for their detection. It is only a matter of time before they are developed for geolocating the submarines of adversarial nations.

There are a few hurdles along the way, though. The electromagnetic signals developed as a result of cavitation bubbles can face interference from human-made or naturally occurring electromagnetic noise. The flow of water around the submarine can also be turbulent, which can impact the signals generated. Moreover, if the submarine slows down or stops, it will not generate any detectable signal.