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

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。

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

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 frequency 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.