Comment on “Piezoelectricity as a mechanism on generation of electromagnetic precursors before earthquakes” by J.H. Wang

Abstract

Wang (2021, hereafter JHW) recently investigated elastic–electric coupling (EEC) in terms of the piezoelectric effect to assess both the plausibility of and necessary conditions for generating pre-earthquake electromagnetic phenomena, including variations in the total electron content (TEC). The study considered a 1-D model to simulate the piezoelectric effect, and derived a quantitative relationship between the dislocation and intensity of the electric field. One of JHW's conclusions was that the piezoelectric effect is a potential mechanism for generating previously reported pre-earthquake TEC anomalies. However, the quantitative discussion in JHW contains a serious error. JHW had chosen an incorrect mode between the two solutions during the derivation of a quantitative relationship between the displacement and the electric field, which subsequently led to an incorrect estimation of the ratio of the generated electric field to the displacement. The opposite conclusion to that drawn by JHW is attained when a correct mode is used.