Co-seismic geomagnetic fluctuations and atmospheric disturbances during the 2018 M 6.2 Hualien Earthquake

Chun-Rong Chen,Horng-Yuan Yen,Cheng-Horng Lin,Chieh-Hung Chen,Tsung-Yu Wu,Hung-Hao Hsieh,Jann-Yenq Liu,Bor-Shouh Huang,Strong Wen,Che-Min Lin

doi:10.3319/tao.2019.03.11.01

Abstract

Co-seismic geomagnetic fluctuations and atmospheric disturbances during the 2018 M 6.2 Hualien Earthquake

Highlights

The large ground motion of earthquake could trigger acoustic and/or gravity waves, termed seismo-traveling atmospheric disturbances (STADs), in the neutral atmosphere near the Earth’s surface
During the 2018 M 6.2 Hualien Milun Earthquake event, 9 QuakeFinder systems together with 3 infrasound systems, 2 tiltmeters, and 2 micro-barometers were in well operation
The similarity suggests that the infrasound and the micro-barometer can sensitively record the atmospheric disturbances induced by S-waves

Summary

INTRODUCTION

The large ground motion of earthquake could trigger acoustic and/or gravity waves, termed seismo-traveling atmospheric disturbances (STADs), in the neutral atmosphere near the Earth’s surface. Low sampling rate, co-seismic fluctuations in the geomagnetic field were hard to distinguish from the effect of magnetometer sensor oscillation (Breiner 1964; Eleman 1965), and high resolution (e.g., 1 Hz) observation are necessary for such researches (Iyemori et al 1996). An induction magnetometer recording derivative quantities of the time rate change of the magnetic field has a better performance than a total field or a fluxgate one (i.e., integral quantity) in detecting highfrequency/small pulsations. Note that the induction magnetometer in QuakeFinder with high resolution of 50 Hz is very sensitive and suitable for detecting co-seismic magnetic signatures (Liu et al 2017). Concurrent/co-located measurements of the seismometer, QuakeFinder systems, infrasound systems (micro-barometers), and tiltmeters are employed to record seismic waves, geomagnetic field, induced disturbances in the neutral atmosphere near the Earth’s surface, and surface oscillation, respectively during the M 6.2 Hualien Earthquake

EXPERIMENT SETUP AND OBSERVATION

DISCUSSION

SUMMARY AND CONCLUSION