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利用超导重力数据检测日本Mw9.0地震的低频自由振荡及谱线分裂

DOI: 10.6038/cjg20141002, PP. 3103-3116

Keywords: 低频自由振荡,谱线分裂,日本Mw9.0地震,超导重力观测数据

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Abstract:

准确估计低频自由振荡及谱线分裂是约束地球内部结构和改进地球模型的重要手段.本文利用四个不同台站的超导重力观测数据系统研究了日本Mw9.0大地震激发的低于1.5mHz自由振荡及谱线分裂.研究结果表明:(1)选取适当的数据长度,超导重力观测数据可以检测出低于1.5mHz除1S1以外的所有自由振荡;(2)除0S2、0S3、0S0、2S1、3S1、1S2和0T2外,重点探测出3S2、0S4和1S4谱线分裂的所有谱峰;(3)与PREM模型理论频率相比,0S0观测频率平均向右偏移0.354×10-3mHz,说明PREM理论模型中地幔底部参数与真实地球可能存在微小偏差;(4)3S2的谱线分裂率r为1.485267,比PREM理论谱线分裂宽度约宽50%,表明PREM中地球内核中部介质参数可能存在一定误差,需要进一步改善.另外,quasi-0T2的r为1.254206,比PREM理论谱线分裂宽度约宽25%.

References

[1]  Crossley D, Jensen O, Hinderer J. 1995. Effective barometric admittance and gravity residuals. Physics of the Earth and Planetary Interiors, 90(3): 221-241.
[2]  Dehlen F A, Tromp J. 1998. Theoretical Global Seismology. Princeton, N. J.: Princeton University Press.
[3]  Guo J Y. 2001. Fundamental Geophysics (in Chinese). Beijing: Surveying and Mapping Press.
[4]  He X, Tromp J. 1996. Normal-mode constraints on the structure of the Earth. Journal of Geophysical Research: Solid Earth (1978—2012), 101(B9): 20053-20082.
[5]  Masters T G, Widmer R. 1995. Free oscillations: frequencies and attenuations. AGU Reference Shelf, 1: 104-125.
[6]  Ness N F, Harrison J C, Slichter L B. 1961. Observations of the free oscillations of the earth. Journal of Geophysical Research, 66(2): 621-629.
[7]  Neumeyer J, Bathelmes F, Combrinck L, et al. 2002. Analysis results from the SG registration with the dual sphere superconducting gravimeter at SAGOS (South Africa). Bulletin d'' Informations Marees Terrestres (BIM), 135: 10607-10616.
[8]  Park J, Song T R A, Tromp J, et al. 2005. Earth''s free oscillations excited by the 26 December 2004 Sumatra-Andaman earthquake. Science, 308(5725): 1139-1144.
[9]  Rosat S, Hinderer J, Crossley D. 2002. A comparison of the seismic noise levels at various GGP stations. Bull. Inf. Marées Terrestres, 135: 10689-10700.
[10]  Roult G, Roch J, Tromp J, et al. 2010. Observation of split modes from the 26th December 2004 Sumatra-Andaman mega-event. Physics of the Earth and Planetary Interiors, 179(1): 45-59.
[11]  Sailor R V, Dziewonski A M. 1978. Measurements and interpretation of normal mode attenuation. Geophysical Journal International, 53(3): 559-581.
[12]  Slichter L B. 1967. Spherical oscillations of the Earth. Geophysical Journal of the Royal Astronomical Society, 14(1-4): 171-175.
[13]  Van Camp M. 1999. Measuring seismic normal modes with the GWR C021 superconducting gravimeter. Physics of the Earth and Planetary Interiors, 116(1-4): 81-92.
[14]  Wang D J. 2012. Study of low-frequency Earth free oscillations based on global superconducting gravimeter data (in Chinese). Wuhan: Wuhan University.
[15]  Benioff H, Press F, Smith S. 1961. Excitation of the free oscillations of the earth by earthquakes. Journal of Geophysical Research, 66(2): 605-619.
[16]  Buland R, Berger J, Gilbert F. 1979. Observations from the IDA network of attenuation and splitting during a recent earthquake. Nature, 277(5695): 358-362.
[17]  Chao B F, Gilbert F. 1980. Autoregressive estimation of complex eigenfrequencies in low frequency seismic spectra. Geophysical Journal International, 63(3): 641-657.
[18]  Deuss A, Ritsema J, Van Heijst H. 2013. A new catalogue of normal-mode splitting function measurements up to 10 mHz. Geophysical Journal International, 193(2): 920-937.
[19]  Hu X G, Liu L T, Hinderer J, et al. 2006. Wavelet filter analysis of atmospheric pressure effects in the long-period seismic mode band. Physics of the Earth and Planetary Interiors, 154(1): 70-84.
[20]  Lei X E, Xu H Z, Sun H P. 2002. Check of free oscillation signal with SG data. Chinese Science Bulletin (in Chinese), 47(18): 1432-1436.
[21]  Lei X E, Sun H P, Xu H Z, et al. 2007. Check of Earth''s free oscillations excited by Sumatra—Andaman large Earthquake and discussions on the anisotropy of inner core. Science in China Series D: Earth Sciences (in Chinese), 37(4): 504-511.
[22]  Masters G, Park J, Gilbert F. 1983. Observations of coupled spheroidal and toroidal modes. Journal of Geophysical Research: Solid Earth (1978—2012), 88(B12): 10285-10298.
[23]  Masters T G. 1989. Low-frequency seismology and the three-dimensional structure of the Earth. Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 328(1599): 329-349.
[24]  Okal E A, Stein S. 2009. Observations of ultra-long period normal modes from the 2004 Sumatra—Andaman earthquake. Physics of the Earth and Planetary Interiors, 175(1-2): 53-62.
[25]  Peterson J. 1993. Observation and modeling of seismic background noise. Albuquerque, U. S.: Department of Interior Geological Survey.
[26]  Resovsky J S, Ritzwoller M H. 1998. New and refined constraints on three-dimensional Earth structure from normal modes below 3 mHz. Journal of Geophysical Research: Solid Earth (1978—2012), 103(B1): 783-810.
[27]  Ritzwoller M, Masters G, Gilbert F. 1986. Observations of anomalous splitting and their interpretation in terms of aspherical structure. Journal of Geophysical Research: Solid Earth (1978—2012), 91(B10): 10203-10228.
[28]  Rosat S, Hinderer J, Rivera L. 2003. First observation of 2S1 and study of the splitting of the football mode 0S2 after the June 2001 Peru earthquake of magnitude 8.4.Geophysical Research Letters, 30(21): 1-4.
[29]  Rosat S, Sato T, Imanishi Y, et al. 2005. High-resolution analysis of the gravest seismic normal modes after the 2004 Mw=9 Sumatra earthquake using superconducting gravimeter data. Geophysical Research Letters, 32(13): 1-4.
[30]  Widmer-Schnidrig R. 2003. What can superconducting gravimeters contribute to normal-mode seismology? Bulletin of the Seismological Society of America, 93(3): 1370-1380.
[31]  Xu C, Luo Z C, Zhou B Y, et al. 2013. Detecting spheroidal modes of Earth''s free oscillation excited by Wenchuan earthquake using superconducting gravity observations. Acta Geodaetica et Cartographica Sinica (in Chinese), 42(4): 501-507.
[32]  Xue X X, Hu X G, Hao X G, et al. 2012. Constraining focal mechanism of the 2011 Tohoku earthquake by gravity observations. Chinese J. Geophys. (in Chinese), 55(9): 3006-3015.

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