【摘要】 在对滇东北地区地下流体观测资料进行综合评估的基础上,选择评估达到Ⅰ、Ⅱ类的观测资料,采用日值、五日均值、旬均值、相关矩平、K-L拟合分析、CF分析等方法,对2003~2012年以来滇东北地区的5组MS≥5.0地震进行震例回顾总结。归纳震前该区地下流体前兆异常的时空演化特征,发现前兆异常数量在时间上具有阶段性,异常项数在震前6个月开始增多,震前3个月达到最大值,临震前1个月部分异常转折结束,异常数量出现降低;异常在空间演化上具有震前3个月向震中收缩的特点。80%的震例表明震中距100 km范围内的观测点异常比例远高于100 km范围外的观测点异常比例。将结果外推应用于2014年8月3日鲁甸6.5级地震,发现他们具有较好的一致性,表明滇东北地区MS≥5.0地震前地下流体的异常特征具有普适性。更多还原

【Abstract】 Based on a comprehensive evaluation about the underground fluid observation data in Northeast Yunnan area,we selected the observation data whose evaluation achieved class I and II,and reviewed and summarized five groups of MS≥5 earthquakes from 2003 to 2012 to conclude the temporal spatial evolution characteristics of precursory anomalies of underground fluid in the study area by using the method of the daily value,the mean value of five days,the mean value of ten days,correlation departure,K- L fitting analysis,CF analysis. The results showthat the quantity of precursory anomaly varied with stages in time. The abnormal items began to increase in the six months and reached a maximum value in the three months before the earthquake,however,some abnormal items turned over and the abnormal quantity decreased in the one month before the earthquake. The spatial evoluation characteristic of precursory anomaly was concentrating from outside to the epicenter in the three months before earthquake. The 80% earthquake cases showthat the proportion of precursory anomaly of observation points within 100 km from the epicenter is far higher than that outside 100 km from the epicenter. The result was used for Yunnan Ludian MS6. 5 earthquake on Aug. 3,2014,we found that they have good consistency,which indicated that abnormal characteristics of the underground fluid before M ≥5. 0 earthquakes in the Northeast Yunnan could be applied widely更多还原