Viscous remanent magnetization is regarded as noise. The information these domains represent is commonly called magnetic remanence or remanent magnetization. Ferromagnetic minerals such as magnetite also can carry a remanent magnetization or remanence. Viscous remanent magnetization is the result of jumps between magnetic states driven by thermal fluctuations. This is called "detrital remanent magnetization". Natural remanent magnetization forms the basis of paleomagnetism and magnetostratigraphy. Another kind of laboratory remanence is "anhysteretic remanence" or "anhysteretic remanent magnetization (ARM)". The natural remanent magnetization of an igneous rock can be altered by this process. It is called the "initial remanence" or the "isothermal remanent magnetization (IRM)". Therefore, a remanent magnetization will be present even after removing the external magnetic field. Remanence that is acquired at a fixed temperature is called "isothermal remanent magnetization (IRM)". Samples are first analyzed in their natural state to obtain their natural remanent magnetization (NRM). This remanent magnetization, or "remanence", can be acquired in more than one way. The field is said to be recorded by "chemical remanent magnetization" (CRM). The field is said to be recorded by "chemical remanent magnetization (CRM)".