viscous remanent magnetization
Also found in: Acronyms.
viscous remanent magnetization[′vis·kəs ′rem·ə·nənt ‚mag·nəd·ə′zā·shən]
A process in which grains of magnetic minerals, which are either too small or too finely divided by undergrowths of different chemical composition to retain a permanent magnetization indefinitely, acquire a new direction of magnetization when the direction of the earth's magnetic field changes. Abbreviated VRM. Also known as viscous magnetization.