Lithospheric geomagnetic field variation in the North-South Seismic Belt from 2010 to 2016

This paper processed six issues of annual variation data of lithospheric magnetic field from 2010 to 2016 in the North-South Seismic Belt （21°N−37°N, 97°E−109°E） by using wavelet decomposition, and systematically analyzed the annual variation of lithospheric magnetic field in epicenters of strong earthquakes （M_S≥5.0） since June of 2011. The results show that correlative coefficients between earthquake magnitude and lithospheric magnetic field components ΔX, ΔY, ΔZ are 0.26, −0.26, 0.15, respectively, which means there is no significant correlation between the two parameters; the maximum variation amplitude of lithospheric magnetic field components ΔX, ΔY, ΔZ in the epicenters of strong earthquakes are 18.46, 14.98, −15.54 nT, respectively. The wavelet decomposition results show that there is significant variation on basic layers with maximum scale of one thousand kilometers in two years before M_S7.0 earthquakes, and significant variation also appears on basic layer in one year before M_S6.0 earthquakes, but the scale is smaller; as to before M_S5.0 earthquakes, no significant anomalies have been found on basic layer or middle layer.