流动重力-地磁场耦合效应在地震短临预测中的应用OA

Based on multi-period ground gravity and geomagnetic observation data from 2016 to 2021 in western Yunnan,this study investigates the 2021 Yangbi M6.4 earthquake using a joint analysis method of gravity and magnetic fields.It analyzes the coupling characteristics of the gravity field and geomagnetic field during the seismogenic process and proposes a new short-term and imminent earth-quake prediction method.The synchronously observed gravity and total magnetic intensity variation data were normalized,and the kernel density distribution and correlation coefficient changes of both within the same region were analyzed to study the epicenter location and the imminence of the earth-quake occurrence.The results show that:1)The gravity field changes and total magnetic intensity changes in the epicentral area are coupled,both exhibiting minor variations at the epicenter but signif-icant changes in the surrounding areas.As the time of the earthquake approaches,the trends of both changes become consistent,while they rapidly diverge after the earthquake.2)For the Yangbi earth-quake,within a 1° × 1° grid,the region with the largest overlap area of the annual variation kernel density curves of the gravity and magnetic fields is located between 25°-26°N and 99°-100°E,which is highly consistent with the actual epicenter of the Yangbi earthquake.3)The joint analysis method also demonstrates practical applicability for earthquakes below magnitude 6 in the study area.