Periodic components of aftershocks series intensity

Category: 14-2
A.A. Lyubushin

UDC 550.334

 

 

A.A. Lyubushin

 

Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia

 

Abstract

A method is proposed for detecting periodic components of aftershocks series which is based on the estimate of logarithmic likelihood increments within moving event window (time window containing the fixed number of events).  Examples of applications of the method are presented for case studies of aftershocks after the Sumatra mega-earthquake of 26 Dec 2004 and the induced earthquake near the Koyna Dam (India) on 24 April 1996. Using the method we extracted statistically significant periodic variations of intensity with periods from few hours up to one month which could not be detected by analyzing background seismicity due to small numbers of events.

Keywords: periodic components of intensity, maximum likelihood, aftershocks.

 

References

Cox, D.R. and Lewis, P.A.W., The statistical analysis of series of events, Methuen, 1966.

Cox, D.R., Partial likelihood, Biometrica, 1975, vol. 62, pp. 269–276.

Hawkes, A.G., Spectra of self-exciting and mutually exciting point processes, Biometrica, 1971, vol. 58, pp. 83–90.

Lyubushin, A.A., Pisarenko, V.F., Ruzhich, V.V. and Buddo, V. Yu., Identification of Periodicities in the Seismic Regime, Vulkanol. Seismol., 1998, no. 1, pp. 62–76.

Vere-Jones, D. and Ozaki, T, Some examples of statistical estimation applies to earthquake data. Cyclic Poisson and self-exciting models, Ann. Inst. Statist. Math., 1982, vol. 34, Part B, pp. 189–207.

Wilks, S.S., Mathematical Statistics, New York: Wiley, 1962.