Abstract From May 2021 to January 2022, Madoi MS7.4, Delingha MS5.8 and Menyuan MS6.9 earthquakes occurred in Qinghai. To further explore the relationship between earthquake and magnetism, we use the three component vector data of mobile geomagnetic field from 2019 to 2021 to explore the temporal and spatial distribution characteristics of regional basic magnetic field and lithospheric magnetic field. We further explore the relationship between the annual variation of each component of lithospheric magnetic field and moderately strong earthquakes in this region. We find that the temporal and spatial distribution of the basic magnetic field in the three periods is very similar. The latest lithospheric magnetic field data before the earthquake shows that the amplitude of H vector at the epicenter of moderate and strong earthquakes changed weakly and the direction turned. The epicenter location is within 200 km from the zero line of D, I, F and Z components. The epicenter distance of Madoi MS7.4 and Menyuan MS6.9 earthquakes are only 5 km and 20 km from the zero line of Z component. In addition, it is found that some lithospheric magnetic field components show obvious anomaly one year before two strong earthquakes.
ZHANG Yu,CHEN Shuanggui,YAN Wansheng et al. Temporal and Spatial Distribution Characteristics of Flowing Geomagnetic Field in Part of Qinghai, Gansu Province[J]. jgg, 2023, 43(1): 65-70.
ZHANG Yu,CHEN Shuanggui,YAN Wansheng et al. Temporal and Spatial Distribution Characteristics of Flowing Geomagnetic Field in Part of Qinghai, Gansu Province[J]. jgg, 2023, 43(1): 65-70.
