Abstract: This paper analysed the characteristics of spatio-temporal evolving of low-point displacement anomaly and the intrinsic and extrinsic equivalent eddy electric current system of the Earth, and proposed the “electromagnetism effect of stove” to explain the cause of low-point displacement. Solar quiet daily variation(Sq), originated from the intrinsic and extrinsic eddy electric current system of the Earth, as an ongoing and alternating magnetic field, cutting the high conducting and low velocity block in the deep of crust, produces the eddy electric current, and creates heat energy. The heat energy results in the unceasingly rising of temperature and pressure,finally has the material phase transition, and causes the conductivity change, and also leads the eddy electric current system to evolve from single eddy electric current system to double and more eddy electric current system. This might be the cause of low-point displacement anomaly in daily variation of Z component of geomagnetic field.

Key words: Geomagnetic low-point displacement, Sq equivalent electric current system, Electromagnetism effect of stove, Material phase transition, Earthquake