地震和爆炸的P波层析成像——第二部分:由时频地震图得到的2004年苏门答腊-安达曼地震的断层破裂特征(英文)
|
摘要
本文分析了2004年12月26日苏门答腊-安达曼地震的宽频带地震图。目的是通过不同频率成分的子事件的发生时间了解断层的破裂过程。具体分析的是由相应宽频带地震记录得到的P波的时频地震图。分析结果说明,在S波到达前的时窗内发生了最大辐射强度的相应频率低于1 Hz的15次较大子事件,但在同样的时窗内,还发生了最大辐射强度的频率更高的数百次小事件,形成了准连续的次声频率的蜂鸣声,在远至8 000 km的距离上都还能观测到。由于高频波在射线传播路径上存在较强的吸收,因而可以断定,地震期间有一大部分的地震能量是以蜂鸣声的形式被释放了。
The paper is concerned with the analysis of broadband seismograms of the Sumatra-Andaman earthquake of 26 December 2004.The purpose of the analysis is to recognize the morphology of the faulting process in terms of the time of occurrence and of the frequency content of subevents.The analysis is based on spectral seismograms of P-waves,obtained from the corresponding broadband recordings.It is found that 15 major subevents with maximum radiation intensity at frequencies lower than about 1 Hz occurred during the time window prior to the arrival of the major S-wave.In the same time window however hundreds of subevents took place with maximum radiation intensity at higher frequencies,producing a quasi-continuous "humming" at infrasonic frequencies observable at distances of the order of 8 000 km.In view of the strong absorption of the high frequency waves during the propagation along the ray path,it may be concluded that the "humming" reflects a substantial portion of the seismic energy released during the earthquake.
The paper is concerned with the analysis of broadband seismograms of the Sumatra-Andaman earthquake of 26 December 2004.The purpose of the analysis is to recognize the morphology of the faulting process in terms of the time of occurrence and of the frequency content of subevents.The analysis is based on spectral seismograms of P-waves,obtained from the corresponding broadband recordings.It is found that 15 major subevents with maximum radiation intensity at frequencies lower than about 1 Hz occurred during the time window prior to the arrival of the major S-wave.In the same time window however hundreds of subevents took place with maximum radiation intensity at higher frequencies,producing a quasi-continuous "humming" at infrasonic frequencies observable at distances of the order of 8 000 km.In view of the strong absorption of the high frequency waves during the propagation along the ray path,it may be concluded that the "humming" reflects a substantial portion of the seismic energy released during the earthquake.
引文
[1]Duda SJ.由地震和爆炸激发的地震P波层析成像——第一部分:基本概念与理论[J].CT理 论与应用研究,2007,16(1):25-34.(英文) Duda SJ.Tomography of seismic P-waves from earthquakes and explosions-Part I:Basic Concepts and Theory[J].CT Theory and Applications,2007,16(1):25-34.
[2]Ammon CJ,Ji C,Thio KH,et al.Rupture process of the 2004 Sumatra-Andaman Earthquake[J].Science,2005,308(5725):1133-1139.
[3]Banerjee P,Pollitz FF,Burgmann R.The size and duration of the Sumatra-Andaman earthquake from far-field static offsets[J].Science(New York,N.Y.),2005,308(5729): 1769-1772.
[4]Jeffrey P,Alex ST,Jeroen T,et al.Earth's free oscillations excited by the 26 December 2004 Sumatra-Andaman earthquake[J].Science,2005,308(5725):11-39-1144.
[5]Thorne L,Kanamori H,Ammon JC,et al.The great Sumatra-Andaman earthquake of 26 December 2004[J].Science,2005,308(5725):1127-1133.
[6]Gusev AA,Guseva EM,Panza GF.Size and duration of the high-frequency radiator in the source of the 2004 December 26 Sumatra earthquake[J].Geophysical JournalInternational,2007,170:1119-1128.
[7]Liu N,Chen QF,Niu FL,et al.Rupture of the 2004 Sumatra-Andaman earthquake inferred from direct P-wave imaging[J].Chinese Science Bulletin,2007,52(14):1986-1991.
[8]Rhie J,Dreger D,Bürgmann R,et al.Slip of the 2004 Sumatra-Andaman earthquake from joint inversion of long-period global seismic waveforms and GPS static offsets[J]. Bulletin of the Seismological Society of America,2007,97(1 A SUPPL.):S115-S127.
[9]Bird P.An updated model of plate boundaries[J].Geochemistry,Geophysics,Geosystems, 2003,4(3):1027.
[10]Jeffreys H,Bullen KE.Seismological tables[M].London,UK:British Association for the Advancement of Science,1940:50.
[11]Duda SJ,Nortmann R.Determination of spectral properties of the earthquakes from their magnitudes[J].Tectonophysics,1983,93(3-4):251-275.
[12]Duda SJ,Xu SX.Broadband seismograms,band-pass seismograms,and spectral magnitudes for a selection of 1978-1983 explosions-comparison with worldwide earthquakes[R]. Institute of Geophysics,University Hamburg.
[13]Duda SJ,Kaiser D.Spectral magnitudes,magnitude spectra,and earthquake quantification:The stability issue of the corner period and of the maximum magnitude for a given earthquake[J].Tectonophysics,1989,166(1):205-211.
[14]Fasthoff S,郭履灿.论震波频谱图—地震波的三维显示[J].CT理论与应用研究,2001, 10(3):47-51.(英文) Fasthoff S,Guo LC.On spectral seismograms-3D display of seismogram[J].CT Theory and Applications,2001,10(3):47-51.
[15]Jenkins G,Watts DG.Spectral analysis and its applications[M].San Francisco,USA: Holden-Day,1968:525.
[16]Aki K,Richards PG.Quantitative seismology:Theory and methods[M].Vol.I and II. San Francisco,USA:W.H.Freeman and Company,1980:932.
[17]B th M.Introduction to seismology[M].Birkh user Verlag,Basel.Switzerland.1973: 395.
[18]Duda SJ,Yanovskaya TB.Spectral amplitude-distance curves for P-waves:effects of velocity and Q-distribution[J].Tectonophysics,1993,217(3-4):255-265.
[19]Kennett B,Engdahl E.Traveltimes for global earthquake location and phase identification[J].Geophysical Journal International,1991,105:429-465.
[20]Krüger F,Ohrnberger M.Tracking the rupture of the M w=9.3 Sumatra earthquake over 1,150 km at teleseismic distance[J].Nature,2005,435(7044):937-939.
[21]Tsai CV,Meredith N,Ekstr m G,et al.Multiple CMT source analysis of the 2004 Sumatra earthquake[J].Geophysical Research Letters,2005,32(17):1-4.
[22]Ishii M,Shearer MP,Heidi H,et al.Extent,duration and speed of the 2004 Sumatra-Andaman earthquake imaged by the Hi-Net array[J].Nature,2005,435(7044): 933-936.
[23]Herrmann RB,Ammon CJ.GSAC Generic seismic application coding,(version 3.30): Computer programs in seismology[R].2007:201.
[24]Wessel P,Smith WF.The generic mapping tools GMT(version 3):Technical reference and cookbook[M].1995:77.
[25]Wessel P,Smith WF.The generic mapping tools GMT[J].Reference manual pages.1995(version 3).
[2]Ammon CJ,Ji C,Thio KH,et al.Rupture process of the 2004 Sumatra-Andaman Earthquake[J].Science,2005,308(5725):1133-1139.
[3]Banerjee P,Pollitz FF,Burgmann R.The size and duration of the Sumatra-Andaman earthquake from far-field static offsets[J].Science(New York,N.Y.),2005,308(5729): 1769-1772.
[4]Jeffrey P,Alex ST,Jeroen T,et al.Earth's free oscillations excited by the 26 December 2004 Sumatra-Andaman earthquake[J].Science,2005,308(5725):11-39-1144.
[5]Thorne L,Kanamori H,Ammon JC,et al.The great Sumatra-Andaman earthquake of 26 December 2004[J].Science,2005,308(5725):1127-1133.
[6]Gusev AA,Guseva EM,Panza GF.Size and duration of the high-frequency radiator in the source of the 2004 December 26 Sumatra earthquake[J].Geophysical JournalInternational,2007,170:1119-1128.
[7]Liu N,Chen QF,Niu FL,et al.Rupture of the 2004 Sumatra-Andaman earthquake inferred from direct P-wave imaging[J].Chinese Science Bulletin,2007,52(14):1986-1991.
[8]Rhie J,Dreger D,Bürgmann R,et al.Slip of the 2004 Sumatra-Andaman earthquake from joint inversion of long-period global seismic waveforms and GPS static offsets[J]. Bulletin of the Seismological Society of America,2007,97(1 A SUPPL.):S115-S127.
[9]Bird P.An updated model of plate boundaries[J].Geochemistry,Geophysics,Geosystems, 2003,4(3):1027.
[10]Jeffreys H,Bullen KE.Seismological tables[M].London,UK:British Association for the Advancement of Science,1940:50.
[11]Duda SJ,Nortmann R.Determination of spectral properties of the earthquakes from their magnitudes[J].Tectonophysics,1983,93(3-4):251-275.
[12]Duda SJ,Xu SX.Broadband seismograms,band-pass seismograms,and spectral magnitudes for a selection of 1978-1983 explosions-comparison with worldwide earthquakes[R]. Institute of Geophysics,University Hamburg.
[13]Duda SJ,Kaiser D.Spectral magnitudes,magnitude spectra,and earthquake quantification:The stability issue of the corner period and of the maximum magnitude for a given earthquake[J].Tectonophysics,1989,166(1):205-211.
[14]Fasthoff S,郭履灿.论震波频谱图—地震波的三维显示[J].CT理论与应用研究,2001, 10(3):47-51.(英文) Fasthoff S,Guo LC.On spectral seismograms-3D display of seismogram[J].CT Theory and Applications,2001,10(3):47-51.
[15]Jenkins G,Watts DG.Spectral analysis and its applications[M].San Francisco,USA: Holden-Day,1968:525.
[16]Aki K,Richards PG.Quantitative seismology:Theory and methods[M].Vol.I and II. San Francisco,USA:W.H.Freeman and Company,1980:932.
[17]B th M.Introduction to seismology[M].Birkh user Verlag,Basel.Switzerland.1973: 395.
[18]Duda SJ,Yanovskaya TB.Spectral amplitude-distance curves for P-waves:effects of velocity and Q-distribution[J].Tectonophysics,1993,217(3-4):255-265.
[19]Kennett B,Engdahl E.Traveltimes for global earthquake location and phase identification[J].Geophysical Journal International,1991,105:429-465.
[20]Krüger F,Ohrnberger M.Tracking the rupture of the M w=9.3 Sumatra earthquake over 1,150 km at teleseismic distance[J].Nature,2005,435(7044):937-939.
[21]Tsai CV,Meredith N,Ekstr m G,et al.Multiple CMT source analysis of the 2004 Sumatra earthquake[J].Geophysical Research Letters,2005,32(17):1-4.
[22]Ishii M,Shearer MP,Heidi H,et al.Extent,duration and speed of the 2004 Sumatra-Andaman earthquake imaged by the Hi-Net array[J].Nature,2005,435(7044): 933-936.
[23]Herrmann RB,Ammon CJ.GSAC Generic seismic application coding,(version 3.30): Computer programs in seismology[R].2007:201.
[24]Wessel P,Smith WF.The generic mapping tools GMT(version 3):Technical reference and cookbook[M].1995:77.
[25]Wessel P,Smith WF.The generic mapping tools GMT[J].Reference manual pages.1995(version 3).
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心