摘要
首先利用叠加谱比法,对成都数字地震台网的12个台站及中国数字地震台网的5个台站所记录的504个宽带垂直分量进行分析,得到与各路径相对应的椭圆内的Lg尾波Q0和η的测量值,再应用反投影技术反演得出四川及邻区Lg尾波Q0和η的分布图像。结果表明Q0值的分布与构造活动性紧密相关,在所研究的范围内,Q0值在225～400的范围内变化。低的Q0值(225～250)发生在安宁河断裂、龙门山断裂和鲜水河断裂的交汇区域,以及由安宁河断裂和则木河断裂等多条断裂所组成的南北向断裂带;在川东的四川盆地,Q0值有所升高,在250～300的范围内变化;在所研究区域东南部的扬子地台,Q0值呈现出350～400的较高值。η值在04～08的范围内变化。绝大部分地区的η和Q0反向相关。
We use the stack spectral ratio method to analyze 504 broad-band vertical components recorded by 12 stations in Chengdu Digital Seismological Network and 5 stations of China Digital Seismological Network, and obtain the measuring values of Q_0 and η of Lg coda in the ellipses corresponding to each path. Then we employ back-projection technique to invert and obtain the distribution images of Q_0 and η of Lg coda in Sichuan and its adjacent regions. The results indicate the distribution of Q_0 correlates with the tectonic activity closely. Q_0 varies between 225 and 400 in the studied area. There exists a low Q_0-value in the junction of the Anninghe fault, Longmenshan fault, and Xianshuihe fault, and the north-southern fault band consisting of various faults, including the Anninghe fault and Zemuhe fault. Q_0 increases slightly in the Sichuan basin of the eastern Sichuan, about 250～300. Q_0 exhibits higher values (350～400) in the Yangtse platform in the southeastern portion of the studied area.η varies in the range of 0.4～0.8. In the most part of the area,η correlates with Q_0 inversely.
出处
《地震研究》
CSCD
北大核心
2005年第1期38-42,共5页
Journal of Seismological Research
基金
国家自然科学基金(49974012和40274030)
云南省自然科学基金(99D0013M)联合资助.
关键词
LG尾波
Q值
叠加谱比法
反投影技术
四川及邻区
Lg coda
value Q
stack spectral ratio method
back-projection technique
Sichuan and vicinity
