云南地区尾波Q_c值的分布特征及其初步解释  

The distribution characteristics and its elementary interpretation of Coda Q_c in Yunnan Region

作　　者：马宏生[1] 刘杰[2] 张国民[1] 王新岭[1] 王伟君[1] 王辉[1] 

机构地区：[1]中国地震局地震预测研究所 [2]中国地震台网中心,北京10036

出　　处：《地震》2006年第3期37-43,共7页Earthquake

基　　金：科技部社会公益项目(2004DIA3J010);地震科学联合基金(106016)

摘　　要：利用云南地区22个区域数字地震台站记录到的,自1999年下半年至2003年年底的5 668个地震数字波形资料,采用Sato单次散射模型,计算了各台站周围50 km内1 371条地震记录的尾波Qc值。依据Q0和η值的不同,将得到的Qc值进行分类。其分类结果显示云南地区的介质结构具有区域性分布特征,而且可以从地质构造、地震活动以及大地热流分布等方面对其予以初步解释。结果表明,在构造复杂、活动强烈的滇中块体及其周边变形带上的Qc值显著小于构造活动一般的其他区域;就地震活动性而言,高Qc值的区域通常没有地震发生或者仅仅发生较低震级的地震,而低Qc值的区域则有较大地震发生;此外,云南地区Qc值的分布与大地热流分布也有负对应关系,即高热流区域的Qc值低,低热流区域的Qc值高。The coda-wave attenuation quality factor Qc in Yunnan region is estimated using the single-scattering attenuation model of Sato based on 5 668 local seismic events recorded by 22 regional digital seismic stations from the later half of 1999 to 2003. The events used in this paper are situated within epicentral distances of 50 km. According to the variation of Q0 and η, we classified the quality factor Qc into two types. The classified results show that there are regional distribution characteristics in medium structure in Yunnan region, and the characteristics could be elementarily interpreted by geological structures, seismic activity and heat flow. Generally speaking, the quality factor Qc in Dianzhong center Yunnan region Block and its boundary area is notably less than that in other regions, where the tectonic activity isn＇t intense. According to seismic activity, there are large earthquakes in the areas with lower Qc, and there are few or only some little earthquakes in the areas with higher Qc. Besides, there is negative relation between quality factor Qc and heat flow in Yunnan region, namely higher heat flow corresponds to lower Qc and lower heat flow corresponds to higher Qc.

关 键 词：尾波Qc Sato单次散射模型 区域性分布 云南地区 

分 类 号：P315.7[天文地球—地震学]