依舒断裂带北段尾波Q值特征研究

Study on Value of Coda Wave in the Northern Section of Yishu Fault Zone

摘要:

研究表明，地震波穿过构造活动相对稳定地区时，能量衰减不明显且具有高Q值；而穿过构造活动地区时，能量会发生强烈衰减且具有低Q值。本文利用Sato模型对依舒断裂带北段萝北-通河地区15个数字化地震台站记录到的266条M_L≥2.0地震尾波Q_c值进行了分析和研究，发现黑龙江萝北、通河附近地区Q_c值具有明显的复杂性和差异性，且萝北地区Q_c值远低于通河地区Q_c值，其原因一方面与区域构造活动有关，另一方面与区域地壳构造复杂、地下介质破碎、区域应力不断变化有关。本文还讨论了萝北、通河附近地区Q值随着频率变化的关系及Q₀值空间分布特征，有效地分析了该区域介质状态的变化过程，对萝北地区地震活动性的研究和预测有指导意义。

Abstract:

The study shows that when the seismic wave passes through a relatively stable area,the attenuation is not obvious and has a high value. And through the tectonic activity,the energy will be strongly attenuated and have a low value. In this paper,the Sato model was used to record more than two hundred M_L ≥ 3.0 earthquakes recorded by 15 different stations in the north of Luobei-Tonghe area(44°~49°N,126°~136°E). Q_c values were analyzed and studied,and the Q value near Luobei,Heilongjiang have complexity and difference,and the reason is related to regional tectonic activity. Generally speaking,where tectonic activity and seismic activity are strong,the Q value is low. The value of coda wave of the Luobei area is much lower than that of the Tonghe area,which is related to the complex crust structure,the degree of underground media fragmentation and the change of internal stress in the Luobei and Tonghe area. This paper also discusses the relationship between the quality factor and the frequency change,and the spatial distribution characteristics of the quality factor and the Q₀ value are obtained,which can effectively analyze the process of the state of the media in the region,and which is very important for the research and prediction of the seismic activity in the Luobei area.