Analysis of geomagnetic anomalies before the Jianhe M5.5 earthquake

• Published in: 地震科学进展 Vol. 50; no. 5; pp. 12 - 17
• Main Authors: Mingrui Guo, Jiuchang Hu, Xijiao Wang, Long Ma, Guidan Wang, Zaizhuang Zheng
• Format: Journal Article
• Language: Chinese
• Published: Editorial Office of Progress in Earthquake Sciences 01.05.2020
• Subjects: daily ratio of geomagnetic vertical component; geomagnetic low-point displacement; geomagnetic vertical component; ratio and ratio of daily variation amplitude
• ISSN: 2096-7780
• DOI: 10.3969/j.issn.2096-7780.2020.05.003

Daily variation ratio of geomagnetic vertical component （Z） is important in the study of earthquake precursor analysis. The ariation magnetic field makes an induced magnetic field because of the earth conductivity, and the induced magnetic field includes information from outer magnetic field and underground electrical conductivity, so the geomagnetic field Z component reflects more changes of underground activity than other components. The paper processes the geomagnetic vertical component data of partial geomagnetism of south China stations located in the study area by using the ratio of daily variation amplitude method. The results show here existed high value anomaly of load on December 22, 2014, and the earthquake occurred 99 days after the anomaly date. The double low point is the phase and amplitude change of the geomagnetic Z component, from the normal V-shape to the W-type. To change the normal diurnal pattern, 57 days before the earthquake, most regions such as Guizhou, Guangxi, Hainan, Hunan a doubl