摘要
选取距卡帕尔-阿拉善4号井300 km范围内的3次5级地震,400 km内的3次6级地震,约600 km内1次7级地震、1次6级强震群作为震例资料,分析了这些地震前卡帕尔-阿拉善4号井前兆异常特征。结果表明:①对于5级地震,50.0%测项出现前兆异常,水化学、水动态异常各占50.0%。这些异常的58.3%表现为中期异常,41.7%表现为短期异常,无单独临震异常,也无叠加临震异常。异常变化幅度大而明显,且以趋势性上升或下降为主。硅酸和硫酸根在同一地震前异常时间与异常形态相似。②对于6级地震,33.3%测项出现前兆异常,其中水化学异常占38.9%,水动态异常占16.7%。出现的异常57.1%为中期异常,28.6%为短期异常,14.3%为临震异常。异常形态多为脉冲突跳,而仅有少数为趋势性高值异常。各异常项目之间有一定的同步性。③对于7级地震或6级强震群,37.5%测项出现前兆异常。出现的异常83.3%为中期异常,16.7%为短期异常。异常幅度大而明显,异常形态以单值突跳或趋势性为主。
Select 3 earthquakes with Ms5 in range of 300 km, 3 earthquakes with Ms6 in 400 km, 1 earthquake with Ms7 and 1 strong earthquake swarm with Ms6 in 600 km apart from No. 4 well of Kaparr - Alashan as case data, we analyzed characteristic of precursory anomaly before those earthquakes in No. 4 well of Kaparr - Alashan. The result indicated that, ① For 5 magnitude of earthquakes, 50.0 % of items appear precursory anomalies. The anomalies of the hydrochemistry and the water dynamic are 50.0 % respectively. 58.3 % of those anomalies are medium-term. And 41.7% of them are short-term. There does not have alone impending anomaly, and there does not have overlap impending anomaly also. The scope of abnormal changes is big and obvious. And it is mainly by raise and drop of trend. It is similar that the abnormal time and the abnormal shape of the silicic acid and the sulphate before the earthquake. ②For 6 magnitude of earthquakes, 33.3 % of items appear the precursory anomalies. The anomalies of the hydrochemistry are 38.9%. The anomalies of the water dynamic are 16.7%. 57.1% of those anomalies are medium-term. 28.6% of them are short-term. And 14.3% of them are impending. The abnormal shapes are mainly by the pulsatile. Only minority is high value anomaly of the trend. Each abnormal items exists certain synchronism. ③ For 7 magnitude of earthquakes or 6 magnitude of strong earthquake swarms, 37.5 % of items appear the precursory anomalies. 83.3 % of those anomalies are medium-term. 16.7% of them are short-term. The abnormal scope is big and obvious. And it is mainly by the skip of sole value or trend.
出处
《内陆地震》
2006年第4期342-352,共11页
Inland Earthquake
基金
新疆地震科学基金(200501)
