Post by David E. Powell
The Chinese are saying they have a new and better way of Magnetic Detection that they can use to find Submarines.
China isn't the only one working on improved MAD technology:
"The Debye effect could be used hunt submarines using the magnetic signatures of
their wakes. Seawater is salty, full of ions of sodium and chlorine. Because
those ions have different masses, any nudge—such as a passing submarine—moves
some farther than others. Each ion carries an electric charge, and the movement
of those charges produces a magnetic field."
"Work done in Russia, whose navy has long been interested in alternatives to
sonar, suggests the Debye effect can be turned into something quite potent. In
1990, two contributors to the Soviet military magazine Naval Collection wrote
that “as a consequence of the great extent of the wake, it is easier to detect
this anomaly than the magnetic anomaly due to the metallic hull of the
submarine.” That suggests that a well-tuned Debye detector might be able to pick
up a trail from several kilometers back and follow it to find the submarine.
Russia’s claims in this area have long been regarded in the West as exaggerated.
The new American interest suggests they might not have been.
Things are likely to get easier, too: a new generation of high-tech magnetic
sensors based on machines called SQUIDs—“superconducting quantum interference
devices”—should be more sensitive than existing ones."