关中、陕南及周边地区尾波衰减特性(Q_c)研究
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摘要
根据单次散射模型的尾波功率谱分析方法,利用陕西数字地震台网宽频带数字地震波形记录资料,计算了关中陕南及周边地区13个频段的Qc值。结果显示:在2ts~35 s的时间窗内,Q0值在37.54~72.59之间,全区平均值为58.44,在上升运动显著的秦岭山脉值较大,关中盆地和陕南值较小;在2ts~70 s的时间窗内,Q0值在194.74~283.50 之间,全区平均值为186.79,莫霍界面高波速区值较大,低速区和低速梯度带值较小。
According to the method of power spectrum analysis of individual dispersion model,using the wide-band digital waveform data recorded by Shaanxi digital seismograph network, the Q_c values of coda wave in 13 frequency bands in Guanzhong,Shannan and the adjacent areas are estimated. The result shows that the coda Q_0 values are in range of 37.54~78.59 with the average value of 58.44 in the 2t_s~35 s time window,and are higher in Qinling mountain chain region where the ascending motion is marked, otherwise are lower in Guanzhong basin and Shannan area. In the 2t_s~70 s time window, the Q_0 values are in range of 194.74~283.50 with the average value of 186.79,and are higher in wave highvelocity area of moho-discontinuity comparing with lower values in wave lowvelocity area and lowvelocity gradient belt.
According to the method of power spectrum analysis of individual dispersion model,using the wide-band digital waveform data recorded by Shaanxi digital seismograph network, the Q_c values of coda wave in 13 frequency bands in Guanzhong,Shannan and the adjacent areas are estimated. The result shows that the coda Q_0 values are in range of 37.54~78.59 with the average value of 58.44 in the 2t_s~35 s time window,and are higher in Qinling mountain chain region where the ascending motion is marked, otherwise are lower in Guanzhong basin and Shannan area. In the 2t_s~70 s time window, the Q_0 values are in range of 194.74~283.50 with the average value of 186.79,and are higher in wave highvelocity area of moho-discontinuity comparing with lower values in wave lowvelocity area and lowvelocity gradient belt.
引文
[1] AkiK.Analysis of the seismic coda of locad earthquakes asscattered waves[J].J.Geophys.Res.,1969,74:615-631.
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[4] 高龙生,石汝武,华正兴,等.唐山-北京地区Q因子随频率的变化[J].地震学报,1986,8(4):354-365.
[5] 马云生,张天中,张焕生.北京及其周边地区尾波Q值分布特征的研究[J].地震学报,1995,17(4):448-458.
[6] 钱晓东,李白基,秦嘉政.2001年云南施甸MS5.9地震余震序列尾波QC值研究[J].地震地磁观测与研究,2004,25(1):9-17.
[7] 胡家树,丛连理,苏有锦,等.云南及周边地区Lg尾波Q值的分布特征[J].地球物理学报,2003,46(6):809-813.
[8] 张耀国,杨桂珍.利用尾波测定四川部分地区的介质品质因子[J].地震学报,1983,5(3):304-312.
[9] 秦嘉政,李宁,胡克坚.1985年云南禄劝地震余震尾波Q值的某些研究[J].地震学报,1987,9(3):237-251.
[10] 黄才中,葛焕称.中国东部的尾波衰减特征和Qc值估计[J].地震学报,1995,17(2):196-202.
[11] 李松林,樊计昌,惠乃玲,等.滦县地区尾波Q值及其与频率关系的研究[J].地震学报,1990,12(4):357-366.
[12] 曾健,陈天长,韩渭宾,等.成都遥测台网区域尾波衰减特征及QC值研究[J].地震学报,1997,19(3):246-253.
[13] 聂永安,曾健,冯德益.三维尾波散射问题的理论研究[J].地震学报,1995,17(1):83-87.
[14] 袁志祥,薛广盈,丁韫玉,等.渭河断陷及临近地区莫霍界面速度图象[J].地震地质,1995,17(1):446-451.
[2] AkiK,ChouetB.Origin of coda waves: source, attenuation,and scattering effects[J].J.Geophys.Res.,1975,80:3322-3342.
[3] 张天中,高龙生,张卫平.滇西试验场的Q值及其随时间窗的变化[J].地震学报,1990,12(1):12-21.
[4] 高龙生,石汝武,华正兴,等.唐山-北京地区Q因子随频率的变化[J].地震学报,1986,8(4):354-365.
[5] 马云生,张天中,张焕生.北京及其周边地区尾波Q值分布特征的研究[J].地震学报,1995,17(4):448-458.
[6] 钱晓东,李白基,秦嘉政.2001年云南施甸MS5.9地震余震序列尾波QC值研究[J].地震地磁观测与研究,2004,25(1):9-17.
[7] 胡家树,丛连理,苏有锦,等.云南及周边地区Lg尾波Q值的分布特征[J].地球物理学报,2003,46(6):809-813.
[8] 张耀国,杨桂珍.利用尾波测定四川部分地区的介质品质因子[J].地震学报,1983,5(3):304-312.
[9] 秦嘉政,李宁,胡克坚.1985年云南禄劝地震余震尾波Q值的某些研究[J].地震学报,1987,9(3):237-251.
[10] 黄才中,葛焕称.中国东部的尾波衰减特征和Qc值估计[J].地震学报,1995,17(2):196-202.
[11] 李松林,樊计昌,惠乃玲,等.滦县地区尾波Q值及其与频率关系的研究[J].地震学报,1990,12(4):357-366.
[12] 曾健,陈天长,韩渭宾,等.成都遥测台网区域尾波衰减特征及QC值研究[J].地震学报,1997,19(3):246-253.
[13] 聂永安,曾健,冯德益.三维尾波散射问题的理论研究[J].地震学报,1995,17(1):83-87.
[14] 袁志祥,薛广盈,丁韫玉,等.渭河断陷及临近地区莫霍界面速度图象[J].地震地质,1995,17(1):446-451.
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