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

[MIS09-08] Far-field Co-seismic Disturbances in Lithosphere, Atmosphere, and Ionosphere of Mw 7.4 Hualien Earthquake in 2024

*ZHIQIANG MAO¹ (1.China University of Geosciences)

キーワード：Lithosphere-Atmosphere-Ionosphere coupling, Seismo-traveling ionospheric disturbances, MVP-LAI system, Rayleigh wave

Vertical and horizontal co-seismic disturbances in the lithosphere-atmosphere-ionosphere (LAI) after the Mw 7.4 Hualian earthquake were examined using the co-located measurements of the System of Monitoring of Vibrations and Perturbations in Lithosphere, Atmosphere and Ionosphere (MVP-LAI). The system is ~1860 km from the epicenter that includes a seismometer, magnetometer, High-Frequency Doppler sounder, and Global Navigation Satellite System (GNSS) receiver. Results show disturbances of X and Z components of geomagnetic field and Doppler sounding simultaneously intensify near 8 minutes after the arrival of Rayleigh waves, in which the disturbances of Doppler sounding are most pronounced. The dynamic spectrum shows disturbances within the frequency band of ~5–15 mHz, which is common and suggests the resonances on the bottom side of the ionosphere. We also collected data of geomagnetic field and total electron content (TEC) from 16 permanent geomagnetic stations and 20 GNSS receivers in Eastern China to trace the horizontal co-seismic disturbances. The results reveal that disturbances propagate at Rayleigh wave velocity. The prominent co-seismic disturbances in geomagnetic fields and Doppler sounder are detectable farther than those in TEC. This study highlights the benefits of co-located and multiple instruments for investigating the LAI disturbances.