2014年滇东北地区成组地震前兆异常分析

Analysis on the Precursory Anomalies of Group Earthquakes in the Northeast of Yunnan Province in 2014

在分析了2014年4月5日、8月17日永善5.2和5.0级地震及8月3日鲁甸6.5级地震前滇东北地区定点前兆异常的基础上,总结了前兆异常特征。研究结果表明,临近地震发生的短临阶段,前兆异常数量明显增多,永善5.2级地震的异常主要集中出现在震前3个月前后,鲁甸6.5级地震的异常主要集中出现在震前1个月左右;空间上前兆异常分布比较集中,大多观测点有2个以上测项出现异常;鲁甸6.5级地震的异常数量是永善5.2级地震的近2倍,地震震级与异常数量呈正相关;鲁甸6.5级和永善5.0级地震的发震时间相隔14天,震前异常无法明确区分。

In this paper, the fixed point precursory anomalies in Northeast of Yunnan Province before Yongshan 5.2, 5.0 and Ludian 6. 5 earthquakes on 5 April, 17 August and 3 August 2014 respectively are analyzed. At the same time, the characteristics of anomalies are summarized. The result show that during the short time, the quanti- ty of precursory anomalies significantly increased. The anomalies mainly concentrated in period of 3 months before Yongshan 5.2 earthquake, and the anomalies of Ludian 6. 5 earthquake concentrated in about 1 month. More are concentrated in the spatial distribution of anomalies. And most of observation points have 2 or more anomalies. Ab- normal quantity before the Ludian 6.5 earthquake is 2 times that before the Yongshan 5.2 earthquake. The tude is positively correlated with the number of anomalies. Yongshan 5.0 earthquake occurred 14 days after 6. 5 earthquake. Their precursory anomalies cannot be clearly distinguished.