Viscous remanent magnetization
（重定向自Viscous magnetization）
Viscous remanent magnetization (Abbreviated VRM), also known as viscous magnetization, is remanence that is acquired by ferromagnetic materials by sitting in a magnetic field for some time. The natural remanent magnetization of an igneous rock can be altered by this process. This is generally an unwanted component and some form of stepwise demagnetization must be used to remove it.