滇西北强震活动特征及短期震兆研究  

Characteristics of Strong Earthquake Activity in Northwest Yunnan and Study on Short-term Earthquake Precursor

作　　者：刘翔[1] 吴国华[1] 付虹[1] 单连君[2] 

机构地区：[1]云南省地震局,昆明650224 [2]云南大学资源环境与地球科学学院,昆明650091

出　　处：《地震研究》2010年第1期7-13,共7页Journal of Seismological Research

摘　　要：根据历史地震资料研究了滇西北强震活动韵律特征及最近10多年来6.0级以上强震前震中附近中小地震活动空间演化图像。对1986年以来滇西北5.0级以上中强震前该地区M≥3.0和M≥4.0地震的活跃和平静异常以及3级以上震群进行了清理和配套性研究,定量地给出了滇西北强震短期震兆指标。得到以下主要结果:滇西北6.0级以上强震前,在全省4.0级以上地震平静异常阶段或3.0级以上地震活跃阶段,震中附近3级地震比较活跃,并形成明显的条带、围空、密集等地震活动有序分布异常图像;滇西北6.0级以上地震短期异常综合预报量Y≥0.56。短期震兆模型可分为两种:①滇西北3.0级以上地震活跃异常和3～4级震群活动同时出现;②滇西北4级以上地震出现平静异常后又出现3.0级以上地震平静异常。Based on the historical earthquake data, we study the rhythm of strong seismicity in Northwest Yunnan and get the medium-sized earthquake space evolution images in the neighboring region of epicenters before the M≥ 6.0 strong quakes occurred in Northwest Yunnan over the past decade. According to the M≥5.0 strong quakes since 1986, we study the activity and equability anomaly of the M≥3.0 or M≥4.0 earthquakes, and the M≥ 3.0 clusters. The index of short precursor of strong earthquake in northwest Yunnan is given quantitatively. The main results show： （ 1 ） before the M≥6.0 quakes occurred in Northwest Yunnan, the M≥4.0 were in equabili- ty and M≥3.0 were in activity, the Ms3.0 quakes around the potential epicenter were in activity, so the abnor- mal images of orderly distribution of seismic activity were given including the obvious band, void and intensive areas ; （2） the integrated forecasting index Y of the quakes above 6 in short term anomaly in Northwest Yunnan is equal to or greater than 0. 5. There are two types of short term precursor model ; type one, the anomaly of ac- tivity of earthquakes with M ≥ 3.0 appear synchronously with the clusters of earthquakes with 3.0 ≥ M ≥ 4. 0. Type two, in the process of the tranquility of the M≥4. 0 earthquakes, there are intermittent tranquility of M≥ 3.0 earthquakes.

关 键 词：强震 震兆 短期 配套性 滇西北 

分 类 号：P315.75[天文地球—地震学]