2014年安徽霍山M4.3地震异常特征及预测过程总结

Earthquake Precursory Anomaly Characteristic and Summary of Prediction Process of Anhui Huoshan M4.3 in 2014

对2014年4月20日安徽霍山M4.3地震前地震预测意见和预测依据进行了回顾总结。自2013年10月开始,安徽地区小震活跃,相继出现地震条带、地震频度、“霍山地震窗”开窗等3项地震学异常;前兆异常位于震中200km范围内,包括流动重力、流动地磁,蒙城台地电阻率、肥东台定点短水准、地下流体等13项。中期阶段,前兆异常月频次不断增加,具有协调性特征;短临阶段,中期异常趋于结束或测值反向,地下流体异常突出,且异常由外围逐渐向震中迁移;临震阶段,异常月频次转折下降。由此可见,霍山地震前异常特征明显,时间上具有阶段性、协调性特征;空间上具有迁移性特征,异常形态具有重复性特征,为地震三要素预测提供了较好的依据。

Through reviewing and summarizing the opinions and basis of earthquake prediction before the Huoshan M4.3 earthquake on Apr. 20,2014 in Anhui Province,we found the following results:Small earthquakes have been active in Anhui area,and three seismological anomalies,including seismic band,seismic frequency and window opening of Huoshan earthquake,have appeared successively since Oct.,2013. The precursory anomalies are located within 200 km of the epicenter,including 13 items,such as mobile gravity,mobile geomagnetic,ground resistivity at Mengcheng station,short level at Feidong station and underground fluid etc.. In the mid-term phase,the monthly frequency of precursory anomalies is increasing continuously and has the characteristics of coordination. In the short-term and impending phase,the mid-term anomalies tend to end or the measured value is reversed,the underground fluid anomalies are prominent,and the anomalies gradually migrate from the periphery to the epicenter. Entering the impending phase,the monthly frequency of anomalies turns down.It follows that the anomalies were obvious before the huoshan earthquake,and precursory anomalies have the characteristics of stage and coordination in time;and the space is characterized by movement;and the abnormal morphology is characterized by repeatability.It provides a good basis for the prediction of the three elements of the earthquake.