地震波在热弹性介质中的衰减性质及其相应Q值的计算方法  

Attenuation of seismic wave in thermal elastic medium and calculation of the corresponding Q_r Value

作　　者：刘文堂[1] 胡顺田[1] 李军[1] 熊仲华[1] 赵永安[1] 

机构地区：[1]防灾科技学院,河北三河燕郊065201

出　　处：《地震》2008年第2期39-45,共7页Earthquake

基　　金：河北省教育厅2002年自然科学研究指导性计划项目(Z2002105)

摘　　要：该文得出热弹性介质中波的基本形式有准弹性纵波、横波和具有有限传播速度的温度波,并指出横波在传播过程中同其在完全弹性介质中一样是不衰减的,而准弹性纵波和温度波是相互伴随的、衰减的。其次,给出了具有两种不同传播速度的准弹性纵波的基本形式。最后,将地震P波看作由初始位移扰动的准弹性纵波,就固定频率和固定波长两种情况分别给出了相应Qr值的计算公式和近似公式。通常人们是利用多台的地震波资料在空间域中计算Qr值,而本文得到的时间域中Qr值的近似公式,为利用单台地震P波资料计算Qr值提供了一种方法。At first, the paper indicates that in the thermoelastic medium, the basic forms of waves include the quasi-elastic longitudinal wave, transverse wave and the wave of temperature with a finite propagate velocity. The paper also indicates that the transverse wave does not attenuate in the process of propagation as in the purely elastic medium, but the quasi-elastic longitudinal wave and the temperature wave are concomitant and attenuate. Second, the paper points out two basic forms of the quasi-elastic longitudinal wave, which has two different propagate velocity. Finally, the seismic P-wave is regarded as the quasi-elastic longitudinal wave, which is excited from the initial displacements. Both fixed fre- quency and wavelength are supplied with calculating and approximating formulas for relevant Qr. The approximate formula of Qr the time-region provides a method for calculating Qr value by using the seismic P-wave data from single seismic observation station.

关 键 词：热弹性介质 地震波 衰减性质 Qr值 

分 类 号：P315.7[天文地球—地震学]