[M-IS09] Interdisciplinary studies on pre-earthquake processes

[MIS09-14] Magnetic field anomalies simulation in ULF band of ionosphere before Madoi earthquake by induced current

*Kaiguang Zhu¹、Ting Wang¹、Wenqi Chen¹、Pu Wang¹、Donghua Zhang¹、Baiyi Yang¹、Yiqun Zhang¹、Yuqi Cheng¹ (1.Jilin University)

キーワード：Lithosphere-atmosphere-ionosphere coupling, Madoi earthquake, Induced current, Resistivity change, Magnetic field anomaly, ULF

The increasing maturity of air-to-ground electromagnetic detection, ionospheric magnetic field anomalies before earthquakes have become one of the key concerns in the seismic field. However, the magnetic field anomalies in the ionospheric ULF band obtained by the simulation of the lithosphere-atmosphere-ionospheric electromagnetic coupling model are still at least one magnitude lower than the observed values. In order to explain the magnetic field anomalies observed before the earthquake, we took the 2021 Ms7.4 Maduo earthquake as an example and proposed the current induced by a large area of pre-seismic resistivity reduction. Finite element software COMSOL Multiphysics was used to simulate the frequency domain propagation characteristics of electromagnetic waves generated by the current through the lithosphere, atmosphere and ionosphere, and simulated the amplitude and waveform of the pre-earthquake anomalies in the time domain which is consistent with the observed values. This will help indentiy magnetic field anomalies.