Bayesian and Frequentist Approaches for the Estimation of the Maximum Expected Earthquake Magnitude in Iran

Document Type : Research Note

Authors

International Institute of Earthquake Engineering and Seismology

Abstract

The maximum earthquake magnitude plays a crucial role in different aspects of seismic hazard and risk assessments. Previous work by Salamat et al. [1] shows the divergence of the confidence interval of the maximum possible earthquake magnitude M(max )for high levels of confidence 1-α, in different seismotectonic zones of Iran. For this, M_(max ) is replaced by the maximum expected earthquake magnitude μ_t  that is calculated for different predefined future time intervals〖 T〗_f. In this work, the frequentist and Bayesian approaches are applied to calculate the upper bound of the confidence interval of 〖 μ〗_t. The frequentist confidence intervals are calculated for the level of confidence 1-α=95% and 99%, and future time intervals T_f=30,50 years. In the Bayesian approach, the posterior distributions of the maximum expected earthquake magnitude are calculated for T_f=30,50 years and 90% confidence level. The stationary Poisson process in time and Gutenberg Richter relation are assumed as a statistical model for the magnitude distribution. In order to estimate μ_t  in each seismotectonic zone, three different scenarios of M_max=8.5,9.0,9.5 are assumed. In order to find the influence of the declustering, all calculations are applied for both original and declustered catalogs. The results show, as long as the length of the time interval is short or moderate, different values of〖 M〗_max have a minor effect on the estimation of the maximum expected earthquake magnitude μ_t. 

Keywords


  1. Ambraseys, N.N. and Melville, C.P. (1982) A History of Persian Earthquakes. Cambridge: Cambridge University Press.
  2. Kijko, A. (2004) Estimation of the maximum earthquake magnitude, Mmax. Pure and Applied Geophysics, 161(8), 1655-1681.
  3. Kijko, A. and Singh, M. (2011) Statistical tools for maximum possible earthquake magnitude estimation. Acta Geophysica, 59(4), 674-700.
  4. Zöller, G. and Holschneider, M. (2015) The earthquake history in a fault zone tells us almost nothing about mmax. Seismological Research Letters, 87(1), 132-137.
  5. Salamat, M. Zare, M., Holschneider, M. and Zöller, G. (2017) Calculation of Confidence Intervals for the Maximum Magnitude of Earthquakes in Different Seismotectonic Zones of Iran. Pure and Applied Geophysics, 174(3), 763-777.
  6. Holschneider, M., Zöller, G., and Hainzl, S. (2011) Estimation of the maximum possible magnitude in the framework of a doubly truncated Gutenberg–Richter model. Bulletin of the Seismological Society of America, 101(4), 1649-1659.
  7. Gutenberg, B. and Richter, C.F. (1956) Earthquake magnitude, intensity, energy, and acceleration (second paper). Bulletin of the Seismological Society of America, 46(2), 105-145.
  8. Pisarenko, V.F. (1991) Statistical evaluation of maximum possible earthquakes. Izvestiya Phys: Solid Earth, 27, 757–763.
  9. Pisarenko, V. Lyubushin, A. Lysenko, V. and Golubeva, T. (1996) Statistical estimation of seismic hazard parameters: maximum possible magnitude and related parameters. Bulletin of the Seismological Society of America, 86(3), 691-700.
  10. Zöller, G., Holschneider, M., and Hainzl, S. (2013) The maximum earthquake magnitude in a time horizon: Theory and case studies. Bulletin of the Seismological Society of America, 103(2A), 860-875.
  11. Pisarenko, V.F.A., Sornette, D., Sornette, A., and Rodkin, M.V. (2008) New approach to the characterization of Mmax and of the tail of the distribution of earthquake magnitudes. Pure and Applied Geophysics, 165, 847–888.
  12. Aki, K. (1965) Maximum likelihood estimates of b in the formula Log N=a - bM and its confidence limits. Bulletin Earthquake Research Institute, 43, 237-239.
  13. Mirzaei, N., Mengtan, G., and Yuntai, C. (1998) Seismic source regionalization for seismic zoning of Iran: Major seismotectonic provinces. Journal of Earthquake Prediction Research, 7, 465-495.
  14. Tavakoli, B. and Ghafory Ashtiany, M. (1999) Seismic hazard assessment of Iran. Annals of Geophysics, 42(6).
  15. Shahvar, M.P., Zare, M. and Castellaro, S. (2013) A unified seismic catalog for the Iranian plateau (1900–2011). Seismological Research Letters, 84(2), 233-249.
  16. Gardner, J. and Knopoff, L. (1974) Is the sequence of earthquakes in Southern California, with aftershocks removed, Poissonian? Bulletin of the Seismological Society of America, 64(5), 1363-1367.
  17. Hessami, K. and Jamali, F. (2006) Explanatory notes to the map of major active faults of Iran. Journal of Seismology and Earthquake Engineering, 8(1).
  18. Zöller, G., Holschneider, M., Hainzl, S., and Zhuang, J. (2014) The largest expected earthquake magnitudes in Japan: The statistical perspective. Bulletin of the Seismological Society of America, 104(2), 769–779.
  19. Kagan, Y.Y. and Schoenberg, F. (2001) Estimation of the upper cutoff parameter for the tapered Pareto distribution. Journal of Applied Probability, 38, 158-175.
  20. Zöller, G. and Holschneider, M. (2016) The maximum possible and the maximum expected earthquake magnitude for production-induced earthquakes at the gas field in Groningen, the Netherlands. Bulletin of the Seismological Society of America, 106(6), 2917-2921.