2018年松原5.7级地震前地磁垂直分量日变化低点时间时空演化特征

本文对松原5.7级地震前地磁垂直分量日变化低点时间时空演化特征进行研究,结果显示:1)以去除经度效应后低点时间为0 h的等值线作为低点位移分界线,松原5.7级地震的震中分别位于2018-04-13分界线上和2018-04-24分界线附近;2)异常日期间,中国大陆地磁垂直分量日变形态存在分区特征,去除经度效应后低点时间为正、负的区域内日变形态分别以“W”型和“V”型为主;3)在2018-04-13和2018-04-24这2个异常日期间,中国大陆都存在去除经度效应后的低点时间高梯度带,松原5.7级地震的震中分别位于2018-04-13高梯度区边缘和2018-04-24高梯度区东侧。

Low-Point Temporal and Spatial Evolution Characteristics of Geomagnetic Vertical Component Diurnal Variation before the Songyuan M5.7 Earthquake

We study the temporal and spatial evolution characteristics of the low point of the daily variation of the geomagnetic vertical component before the Songyuan M5.7 earthquake. The results show that: 1) when the isoline of the low point time 0 h after the longitude effect is removed, the epicenter of the Songyuan M5.7 earthquake is located on the boundary of April 13 and near the boundary of April 24, respectively; 2) during the abnormal day(the geomagnetic vertical component day of the mainland of China), the daily deformation patterns in the region with positive and negative low point time after longitude effect removal are mainly W-shaped and V-shaped respectively; 3) during the two abnormal days of April 13 and April 24, there are high gradient zones with low point time after longitude effect removal in mainland of China, and the epicenter of Songyuan M5.7 earthquake is located at the edge of high gradient zone on April 13, and the east side of high gradient zone on April 24 respectively.