Which factor affects the submarine anomaly?

Which factor affects the submarine anomaly?

• A. Depth of water and current velocity.
• B. Alignment in the Earth's field, size, latitude, and degree of permanent magnetization.
• C. Type of propulsion and hull material.
• D. Weather conditions and sea state.

Answer: (B)

Submarine magnetic anomalies come from the submarine’s magnetic moment interacting with the Earth’s magnetic field. The strength and shape of the observed perturbation depend on four main factors: how the hull’s magnetization is oriented relative to the local Earth field, the size of the hull (which sets how large the magnetic moment is), the latitude (which changes the Earth field’s inclination and intensity at that location), and the degree of permanent magnetization the hull carries. If the hull’s magnetization lines up with the Earth’s field in a way that enhances the perturbation, and the hull is large with a strong remanent magnetization, the anomaly will be more pronounced. In contrast, depth of water or current velocity don’t alter the submarine’s intrinsic magnetic moment, so they don’t determine the anomaly’s magnitude. Weather or sea state likewise doesn’t affect the magnetic signature.

Submarine magnetic anomalies come from the submarine’s magnetic moment interacting with the Earth’s magnetic field. The strength and shape of the observed perturbation depend on four main factors: how the hull’s magnetization is oriented relative to the local Earth field, the size of the hull (which sets how large the magnetic moment is), the latitude (which changes the Earth field’s inclination and intensity at that location), and the degree of permanent magnetization the hull carries. If the hull’s magnetization lines up with the Earth’s field in a way that enhances the perturbation, and the hull is large with a strong remanent magnetization, the anomaly will be more pronounced. In contrast, depth of water or current velocity don’t alter the submarine’s intrinsic magnetic moment, so they don’t determine the anomaly’s magnitude. Weather or sea state likewise doesn’t affect the magnetic signature.