A non-stationary epidemic type aftershock sequence model for seismicity prior to the December 26, 2004 M 9.1 Sumatra-Andaman Islands mega-earthquake

作者：Bansal A R^*; Ogata Y

来源：Journal of Geophysical Research, 2013, 118(2): 616-629.

DOI：10.1002/jgrb.50068

We study temporal changes in seismicity in Sumatra-Andaman Islands region before the M 9.1 earthquake of December 26, 2004. We applied the epidemic type aftershock sequence (ETAS) models to the seismicity. The two-stage non-stationary ETAS model with a single change-point provides a better statistical fit to the seismicity data than the stationary ETAS model throughout the whole period. We made further change-point analysis of data sets by dividing into two sub-regions. The best fitted models suggest that the seismic activation relative to the ETAS rates started in the middle of July 2000 (about 4.5 years before the M 9.1 earthquake). This includes an increase in the background seismicity rates, particularly in the southern part of the seismogenic zone near the epicenter. A space-time ETAS model also suggests that the background seismicity throughout the entire Sumatra-Andaman Islands area had increased after the change-point time. Citation: Bansal, A. R., and Y. Ogata (2013), A non-stationary epidemic type aftershock sequence model for seismicity prior to the December 26, 2004 M 9.1 Sumatra-Andaman Islands mega-earthquake, J. Geophys. Res. Solid Earth, 118, 616-629, doi:10.1002/jgrb.50068.

• 出版日期2013-2