地壳极限应变与危险区强震发生的概率估计  

Ultimate Strain of Crust and the Probability of Strong Earthquakes in Potential Areas

作　　者：张郢珍 张立人[1] 粟生平[1] 李志雄[1] 

机构地区：[1]国家地震局分析预报中心

出　　处：《中国地震》1991年第2期31-36,共6页Earthquake Research in China

摘　　要：本文在中国、日本与美国的破坏性地震极震区的地壳形变观测数据的基础上,用维布尔分布确定了适用于中国的地壳极限应变值为5.25×10^(-5)±2.27×10^(-5)。同时根据文献[2]所确定的17个一级危险区与6个二级危险区中各区的形变速度梯度值与历史地震活动资料,按维布尔分布确定了各危险区未来10—20年内发生强震的累积概率。研究结果表明,目前有二个地区累积概率已高达0.70以上,还有五个地区累积概率在0.30～0.70之间,同时对1989年山西大同-阳高地震与1990年青海共和-兴海地震进行了内符合检验,发现这两个地区到发震时的累积概率均超过了0.54,因而初步显示出本方法的有效性。In this paper, the data of crustal deformation in the meizoseismal regions of China, Japan and the United States are collected. By using Weibull distribution, we calculate the ultimate strain of crust, as 5. 25×10-5±2. 27×10-5. Based on the theory of Weibull distribution and the results in our last article named 'The Velocity Gradient of Vertical Deformation in China and High Risk Areas of Strong Earthquakes', in which 17 first-order risk areas and 6 secondary risk areas were determined, we calculate the accumulative probabilities in each potential area in next ten years and twenty years by means of the velocity gradients of deformation and the historical earthquake data in these areas. According to our results, we obtain that so far there are two high probability areas with accumulative probabilities exceeding 0. 70 and there are still another 5 areas with accumulative probabilities between 0. 30 and 0. 70. At the same time we test the practicability of probability used in this paper to the Datong-Yang-gao earthquake in Shanxi Province (1989) and the Gonghe-Xinhai earthquake in Qinhai Province (1990). The test results show that the method of probability is practicable because the accumulative probabilities exceed 0. 54 from the last strong earthquake to 1990.

关 键 词：地壳极限应变 地震 概率 

分 类 号：P315.2[天文地球—地震学]