Abstract:In this paper,we use observation data for Tianshui geomagnetic station(TSY), Lanzhou geomagnetic station (LZH), Qianling geomagnetic station(QIX), and Chengdu geomagnetic station(CDP), based on multi-scale wavelet decomposition, extraction of time of low-point on vertical compenent,and variation process of low-point shift on time. The results show that the low-point shift continues to lag the vertical compenent on Tianshui geomagnetic station (TSY) from May to July 2013.The range of variation lies beyond the normal state, but other stations do not present this abnormal phenomenon. This process shows localized features at Tianshui station; the Minxian-Zhangxian 2013-07-22 M6.6 earthquake occurrence is on down-point time of low-point shift peak, showing the correlation between the anomaly and the earthquake. This may be a reflection of seismogenics in the geomagnetic field. These results have an important reference value in the study of the seismogenic process, mechanism dynamics process of geomagnetic low point shift, and exploration on earthquake prediction.
XU Kangsheng,ZENG Wenhao. Abnormity of Geomagnitics Low-Point Shift: A Possible Seismogenic Reflection of the Minxian-Zhangxian M6.6 Earthquake[J]. jgg, 2017, 37(4): 425-428.