Very low frequency magnetic pulses have been observed in the run-up to earthquakes since the 1960s. Now, geophysicists claim they have discovered how rocks produce magnetic pulses – go to https://medium.com/the-physics-arxiv-blog/geophysicists-reveal-how-earth… … the new model, it is hoped, will target regions of the crust at immanent risk. However, it is acknowledged it is not entirely certain if rocks produce magnetic pulses when there is no earthquake. It is a developing theory.
Magnetic pulses
8 June 2014Electromagnetism