Abstract Applying the method of harmonic wave amplitude ratio, we calculate the minute-value data derived from Heilongjiang Tonghe geomagnetic station.The results show that before the January 2, 2016 MB6.4 deep source earthquake in Linkou of Heilongjiang province, the harmonic wave amplitude ratio of Tonghe geomagnetic station, about 150 km from the epicenter, presents obvious abnormality. There are four anomaly characteristics: (1) the abnormal change of the harmonic wave amplitude ratio YZHx in the north-south and YZHy in the east-west show the characteristics the form of "down-turning-recovery"; (2) The transition features have the characteristics of migration from deep (long period) to shallow (shorter period) in the abnormal change of harmonic wave amplitude ratio; (3) from March 2014 to January 2016, dielectric properties of the harmonic wave amplitude ratio YZHy data in Tonghe geomagnetic station have a different abnormality at different depths; (4) abnormal amplitude of the harmonic wave amplitude ratio YZHy in Tonghe geomagnetic station is greater than YZHx. The reason for abnormal characteristics is that the western Pacific plate dived under the Eurasian continent at a high speed with a small dip before the MB6.4 deep source earthquake in Linkou. The stress change of the seismogenic body led to electrical properties of the local medium changing near the Tonghe geomagnetic station.
LIU Changsheng,NI Xiaoyin,ZHOU Chen et al. Anomalies of the Geomagnetic Harmonic Wave Amplitude Ratio before the MB6.4 Deep Source Earthquake in Heilongjiang Province[J]. jgg, 2019, 39(3): 290-294.
LIU Changsheng,NI Xiaoyin,ZHOU Chen et al. Anomalies of the Geomagnetic Harmonic Wave Amplitude Ratio before the MB6.4 Deep Source Earthquake in Heilongjiang Province[J]. jgg, 2019, 39(3): 290-294.
