中国西部地区地震烈度衰减关系

摘要

Using intensity data collected from 71 earthquakes after 1991 in western China, together with data from 176 earthquakes from 1918 to 1989 in the same area, a new earthquake intensity attenuation relationship is refitted using an elliptical model in this paper. The result reveals that differences in intensity attenuation relationship can be found between Xinjiang Zone and Chuanzang Zone, suggesting that the two zones should be treated as two different zones when fitting earthquake intensity attenuation relationship in this area. Comparison of our result with previous results shows that the new attenuation relationship gives a more reasonable expression to earthquake intensity distributions in both near and far field, which suggests the new attenuation relationship suitable for earthquake engineering research and application in western China.%本文收集了1991年之后我国西部地区71个地震的烈度等震线资料,并以此对1918-1989年间176次地震的烈度资料进行了补充,采用长、短轴椭圆模型重新拟合了西部地区的分区地震烈度衰减关系.结果表明,新疆区和川藏区2个统计单元内地震烈度衰减关系有显著不同,应作为不同的分区对待.同时与其他研究者给出的该地区地震烈度衰减关系的对比结果显示,本文结果合理可靠,体现了近、远场地震烈度分布的特点,适合于该地区工程地震研究和应用.