Abstract
Calibrating functions for determination of P-wave spectral magnitudes calculated by Duda and Yanovskaya (1994) on the basis of the IASP91 velocity model and the PREM Q-model are verified empirically. For this purpose IRIS broadband records for 120 earthquakes are used, each earthquake having been recorded at about 100 stations. The discrepancies indicate that anelastic absorption assumed in PREM is too high. New calibrating functions are calculated on the basis of the AK135 velocity and anelasticity models (Kennet et al., 1995; Montagner and Kennet, 1996), in which Q in the mantle is higher than in PREM. The verification of the new calibrating functions based on the same observations yields magnitude figures less depending on the epicentral distance. In addition the parameter τ2in the Liu-Anderson Q(T) model is estimated, proceeding from the assumption that on the average the radiated spectra comply with the ω2-model. The value of τ2 was assumed to be 0.1 s in the analysis and its use resulted in the verification of the ω2-model for the source spectrum.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bache, T. C., Marshall, P. D. and Bache, L. B., 1985, Q for teleseismic P waves from Central Asia, J. G. R. v. 90, B5, 3575–3587.
Bache, T. C, Bratt, S. R. and Bungum, H., 1986, Highfrequency Pwave attenuation along five teleseismic paths from central Asia, Geoph. J. R. astr. Soc. 85, 505–522.
Bock, G. and Clemens, J. R., 1982, Attenuation of shortperiod P, PcP and pP waves in the Earth's mantle, J. G. R. 87, B5, 3905–3918.
Douglas, A., 1992, Q for shortperiod Pwaves: is it frequency dependent? G. J. I. 108, 110–124.
Duda, S. J. and Yanovskaya, T. B., 1993, Spectral amplitude-distancecurves for Pwaves: effects of velocity and Q-distribution, Tectonophysics 217, No. 3/4, 255–265.
Duda, S. J. and Yanovskaya, T. B., 1994, Calibrating functions for Pwave spectral magnitudes, Acta Geofizica Polonica v.XLII, N4, 293–306.
Dziewonski, A.M. and Anderson, D. L., 1981, Preliminary reference Earth model, Phys. Earth and Planet. Inter. 25, 297–356.
Grant, J. A. and Mansinha, L., 1977, Seismic magnitudes from Fourier analysis, BSSA Vol. 67, No. 2, 453–461.
Gutenberg, B. and Richter, C. F., 1956, Magnitude and energy of earthquakes, Ann. di Geofisica. 9, 1–15.
Howell, B. F., Lundquist, G.M. and Yiu, S. K., 1970, Integrated and frequencyband magnitude, two alternative measures of the size of an earthquake, BSSA Vol. 60, No. 3, 917–937.
Jansky, J., Kvasnicka, M. and Duda, S. J., 1997, Discussion on features of synthetic amplitudedistance curves of teleseismic Pwaves for global Earth models, Studia geoph. et geodet., in press.
Kennet, B. L. N. and Engdahl, E. R., 1991, Travel times for global earthquake location and phase identification, Geoph. J. Int. 105 429–465.
Kennet, B. L. N., Engdahl, E. R. and Buland, R., 1995, Constraints on seismic velocities in the Earth from traveltimes, Geophys. J. Int., 122, 108–124.
Liu, H.P., Anderson, D. L. and Kanamori, H., 1976, Velocity dispersion due to anelastisity: implication for seismology and mantle composition, Geoph. J. R. astr. Soc. 47, 41–58.
Montagner, J.P. and Kennet, B. L. N., 1996, How to reconcile bodywave and normal mode reference earth models, Geophys. J. Int. 125, 229–248.
Nortmann, R. and Duda, S. J., 1983a, Determination of spectral properties of earthquakes from their magnitudes, Tectonophysics 93, 251–275.
Nortmann, R. and Duda, S. J., 1983b, The anelasticity of the earth’ s mantle in the European area: frequencedependence of Q, Tectonophysics 91, T1–T6.
Pachova, S. V. and Yanovskaya, T. B., 1992, Influence of absorption on the spectral amplitude curves of longitudinal waves, Bulg. Geoph. Journal v. XVIII, No. 2, 13–20.
Roslov, Yu. V., 1994, Program for Amplitude Spectra Treatment and Analysis, Acta Geofizica Polonica v. XLII, N4, 315–319.
Shapira, A. and Kulhanek, O., 1978, Conventional and spectral shortperiod Bodywave magnitudes, BSSA Vol. 68, No. 4, 1195–1198.
Yacoub, N. K., 1983, 'Instantaneous amplitudes': a new method to measure seismic magnitudes. BSSA Vol. 73, No. 5, 1345–1355.
Yanovskaya, T. B. and Duda, S. J., 1994. Q(T) for short periods from broadband observations of Pwaves, Acta Geofizica Polonica v. XLII, N4, 281–292.
Yanovskaya, T. B., Roslov, Yu. V. and Lyskova, E. L., 1996, Earthquake quantification on the basis of Pwave spectra, Izvestiya Physics of the Solid Earth v. 32, No. 1, 1–12.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lyskova, E.L., Roslov, Y.V., Yanovskaya, T.B. et al. Verification and refinement of spectral magnitude calibrating functions for P-waves. Journal of Seismology 2, 117–124 (1998). https://doi.org/10.1023/A:1008054913617
Issue Date:
DOI: https://doi.org/10.1023/A:1008054913617