Multi-Parameter Observations of Seismogenic Phenomena Related to the Tokyo Earthquake (M = 5.9) on 7 October 2021

Multi-parameter observations, powerful for the study of lithosphere–atmosphere–ionosphere coupling (LAIC), have been performed a recent Tokyo earthquake (EQ) with moderate magnitude (M = 5.9) and rather larger depth (~70 km) on 7 October 2021, in hope predicting next Kanto (Tokyo) huge EQ, such as 1923 Great EQ (with greater than 7). Various possible precursors searched during two-month period 1 September to 31 based different kinds data sets: (i) ULF (ultra-low frequency) magnetic from Kakioka, Japan, (ii) ULF/ELF (extremely low field Chubu University network, (iii) meteorological (temperature humidity) Japan Meteorological Agency (JMA), (iv) AGW (atmospheric gravity wave) ERA5 provided by European Centre Medium-Range Weather Forecast (ECMWF), (v) subionospheric VLF/LF (very frequency/low Russia (vi) ionosonde Japanese data, (vii) GIM (global ionosphere map) TEC (total electron content) data. After extensive analyses all above we found that there are few obvious precursors: electromagnetic radiation atmosphere, lower ionospheric perturbations two independent tools depression VLF anomaly) which took place just days before EQ. Further, atmospheric has observed approximately one week until after seems be synchronous time anomalous variation parameters (a combination temperature humidity, chemical potential). On other hand, no clear anomalies detected stratospheric activity, NmF2 upper F region ionosphere. So, it lithospheric origin is not strong enough perturb region. Finally, discuss hypothesis LAIC process, can conclude might ruled out, but channels channel (radon emanation) associated effects operation, at least, this