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
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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 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.
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.
引文
[1]刘建华,胥颐,郝天珧.地震波衰减的物理机制研究[J].地球物理学进展,2004,19(1):001-007.
[2]刘建华,刘福田,胥颐.远震P波衰减因子的测量与Q成像方法[J].地球物理学进展,2004,19(2):304-310.
[3]苏有锦.云南地区S波非弹性衰减Q值研究[J].地震学报,2006,28(2):206-212.
[4]Jackson D D,Anderson D L.Physical Mechanisms of Seismic Wave Attenuation[J].Rev GeophysSpace Phys,1970,8(1):1-63.
[5]Francis P H,Hetnarski R B.Dynamic probleme of Thermoelastisity[M].Waraw Pwn-Polish Scien-tific Publishers,1975.
[6]安艺敬一,理查兹P G.定量地震学[理论和方法].北京:地震出版社,1986.185.
[2]刘建华,刘福田,胥颐.远震P波衰减因子的测量与Q成像方法[J].地球物理学进展,2004,19(2):304-310.
[3]苏有锦.云南地区S波非弹性衰减Q值研究[J].地震学报,2006,28(2):206-212.
[4]Jackson D D,Anderson D L.Physical Mechanisms of Seismic Wave Attenuation[J].Rev GeophysSpace Phys,1970,8(1):1-63.
[5]Francis P H,Hetnarski R B.Dynamic probleme of Thermoelastisity[M].Waraw Pwn-Polish Scien-tific Publishers,1975.
[6]安艺敬一,理查兹P G.定量地震学[理论和方法].北京:地震出版社,1986.185.
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