Global Geomagnetic Disturbances Presumably Caused by Earthquakes

Abstract—The paper examines the possibility of occurrence of global geomagnetic disturbances during earthquakes, events that have been documented by observations and reported in numerous publications in leading Russian geophysical journals. Validation of the above phenomenon could become a significant discovery in geophysics. Therefore, these results require thorough verification. The comparison of the disturbances presented in the publications with the data from high-latitude magnetometer stations has shown that all the morphological features of the long-period disturbances (with quasi periods of 10–40 min) identify them as characteristic manifestations of the activation of the magnetospheric-ionospheric current system in the auroral latitudes. Thus, the detected disturbances represent a mid-latitude response to electrojet variations in the auroral region and are not related to seismic activity. The short-period disturbances (with a characteristic period less than 1 min) proved to be either a coseismic geomagnetic response to a surface seismic wave or a burst of Pc3 pulsations of magnetospheric origin, occasionally coinciding with the occurrence of a distant earthquake. This study clearly demonstrates that the identification of anomalous disturbances requires the efforts of both earthquake physics specialists and space weather experts.