Journal of the Earthquake Engineering Society of Korea (한국지진공학회논문집)

Earthquake Engineering Society of Korea (한국지진공학회)
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Q Estimates Using the Coda Waves in the Kyeongsang Basin

Coda 파를 이용한 경상분지에서의 Q값 추정

  • Published : 1999.03.01
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Abstract

In this study, coda Q has been determined by the single scattering model in the Kyeongsang Basin region using the decay of the amplitudes of coda waves on bandpass-filtered seismograms of local microearthquakes in the frequency range 1.5~18 Hz. Reported frequency dependence of Q is of the form $Q_C=Q_O ^n$$(83.9{ll}Q_0{ll}155.9,;0.76{ll}n{ll}1.05$. Considering a model incorporating both scattering and intrinsic attenuation, and assuming that the attenuation is entirely due to the scattering loss, the minimum mean free paths are about 51~56 km and the coefficients of inelastic attenuation(${\gamma}$) are between 0.0093 and 0.0098 were found. Earthquake-station paths pass through the fault zone show high attenuation and strong frequency dependency compared to other ones.

이 연구에서는 단일 산란이론을 이용하여 경상분지에서 얻어진 국소 미소지진의 자료를 1.5-1.8Hz 사이의 주파수 영역에서 몇 개의 구간으로 나누어 대역 통과 필터링을 g여 coda 파의 진폭 감쇠로부터 Q값을 결정하였다 Coda Q 값은 Qc=Q0 fn 형태의 주파수 의존 양상을 보여주며 Q0 값은 83.9-155.9 n 값은 0.76에서 1.05 사이로 나타났다 산란 감쇠와 고유감쇠를 고려하여 감쇠가 순전히 산란에 의해서만 일어난다고 가정했을 때 최소 평균 자유경로를 51.-56km 이고 비탄성 감쇠계수는 0.0093-0.0098 로 나타났다 진앙과 관측소간의 경로가 단층지역을 지나는 것이 다른 경로를 지나오는 것보다 높은 감쇠와 강한 주파수 의존성을 보여준다.

Keywords

References

  1. Rev. Geophys v.2 Q Knopoffm, L.
  2. J. Geophys. Res. v.74 Analysis of the seismic coda of local earthquakes as scattered waves Aki, K.
  3. J. Geophys. Res v.80 Origin of coda waves: source, attenuation,and scattering effects Aki, K.;Chouet, B.
  4. Bull. Seism. Soc. Am. v.72 Estimates of Q in central Asia as a function of frequency and depth using the coda of locally recorded earthquakes Roecker, S. W.;Tucker, B.;King, J.;Hatzfeld, D.
  5. Bull. Seism. Soc. Am v.73 Q determined from local earth-quakes in the South Carolina coastal plain Rhea, S.
  6. Bull. Seism. Soc. Am. v.78 Attenuation of coda waves in the Dead Sea region Van Eck, T.
  7. J. Phys. Earth v.25 Single isotropic scattering model including wave conversions. Simple theore-tical model of the short-period body wave propagation Sato, H.
  8. Izv. Akad. Nauk SSSR, Fiz. Zemli v.13 The role of multiple scattering in the formation of a seismo-gram's tail Kopnichev, Y. F.
  9. Pure Appl. Geophys. v.121 Effects of multiple scattering on coda waves in three-dimensional medium Gao, L. S.;Biswas, N. N.;Lee, L. C.;Aki, K.
  10. Bull. Seism. Soc. Am. v.73 Comparison of the effects between single and multiple scattering on coda waves for local earthquakes Gao, L. S.;Lee, L. C.;Biswas, N. N.;Aki, K.
  11. Bull. Seism. Soc. Am. v.74 Attenuation of coda waves in New England Pulli, J. J.
  12. Bull. Seism. Soc. Am. v.79 Site-dependent Coda Q at mono craters, California Steck, L. K.;Prothero, W, A.;Scheimer, J.
  13. Bull. Seism. Soc. Am. v.68 The use of the coda for determination of the earthquake source spectrum Rautian, T.G.;Khalturin, V. I.
  14. Bull. Seism. Soc. Am. v.79 Q in Southern Norway Kvamme, L. B.;Havskov, J.
  15. J. Geophys, Res. v.85 Scattering and attenuation of shear waves in the lithosphere Aki, K.
  16. Bull. Seism. Soc. Am. v.73 The apparent attenuation of a scattering medi-um Richards, P. G.;Menke, W.
  17. Geophys. Res. Letters v.11 A scattering model to explain seismic Q observations in the lithosphere between 1 and 30Hz Dainty, A.
  18. The Journal of the Geological Society of Korea v.15 On crustal structure of the Korean peninsula Lee, K.
  19. J. Geophys. Res. v.78 Seismic wave attenuation and magnitude relations for eastern North-America Nuttli, O. W.
  20. KIGAM Research Report, No. KR-94(C)1-16 Seismological study Jun, M. S.;Chi, H. C.;Jeon, J. S.;Shin, I. C.
  21. KAERI Research Report, No. 96-08 Seismic Wave Attenuation in the Korean Peninsula Baag, C. E.