Magnetization, Piezoremanence and Stress Demagnetization
With the advent of paleomagnetic studies in the 1940s, scientists began to wonder how the effect of stress, from burial, folding, etc., would influence the magnetic remanence of rocks. By the mid‐1950s, an intense research effort was underway aimed at understanding piezoremanence, which is the remanent magnetization produced by stress, as well as the opposite effect of stress demagnetization. The laboratory experiments suggested that the magnetic signals of rocks were sensitive to stresses typically found around fault zones; and it was calculated that such stress‐induced changes would in turn modify the local magnetic field. Scientists thought that earthquakes could be predicted by monitoring magnetic‐field variations.
How pressure (stress) affects magnetic remanence
The origin of a spontaneous magnetic remanence is commonly associated with electron exchange between iron (or other transition metals such as Cr, Ni, etc.) atoms. For the iron oxide magnetite (Fe3O4), the most abundant...
- Kean, W., Day, R., Fuller M., and Schmidt, V., 1976. The effect of uniaxial compression on the initial susceptibility of rocks as a function of grain size and composition of their constituent titanomagnetites. Journal of Geophysical Research, 81: 861–872.Google Scholar
- Martin, R., and Noel, J., 1988. The influence of stress path on thermoremanent magnetization. Geophysical Research Letters, 15: 507–510.Google Scholar