Abstract
At the lightning, a strong magnetic field is induced around the path of the pulse current between the cloud and the ground. We investigated the remanent magnetization of the soil and ground material most likely acquired under this magnetic field. Both clockwise and counter-clockwise rotating remanent magnetizations were found, which are believed to be corresponding to the positive and negative polarities of lightning current. The remanent magnetization can be a fossil of lightning current preserved in the ground, so that we can study the underground path of the lightning current through the remanent magnetization.
