TY - JOUR
T1 - A short term seismic hazard assessment in christchurch, New Zealand, after the m 7.1, 4 September 2010 Darfield earthquake
T2 - An application of a smoothing kernel and rate-and-state friction model
AU - Chan, Chung Han
AU - Wu, Yih Min
AU - Lin, Ting Li
PY - 2012/4
Y1 - 2012/4
N2 - The M w 6.3,21 February 2011 Christchurch, New Zealand, earthquake is regarded as an aftershock of the M 7.1,4 September 2010 Darfield earthquake. However, it caused severe damage in the downtown Christchurch. Such a circumstance points out the importance of an aftershock sequence in seismic hazard evaluation and suggests the re-evaluation of a seismic hazard immediately after a large earthquake occurrence. For this purpose, we propose a probabilistic seismic hazard assessment (PSHA), which takes the disturbance of a short-term seismicity rate into account and can be easily applied in comparison with the classical PSHA. In our approach, the treatment of the background seismicity rate is the same as in the zoneless approach, which considers a bandwidth function as a smoothing Kernel in neighboring region of earthquakes. The rate-and-state friction model imparted by the Coulomb stress change of large earthquakes is used to calculate the fault-interaction-based disturbance in seismicity rate for PSHA. We apply this approach to evaluate the seismic hazard in Christchurch after the occurrence of the M 7.1, 4 September 2010 Darfield earthquake. Results show an increase of seismic hazards due to the stress increase in the region around the rupture plane, which extended to Christchurch. This provides a suitable basis for the application of a time-dependent PSHA using updating earthquake information.
AB - The M w 6.3,21 February 2011 Christchurch, New Zealand, earthquake is regarded as an aftershock of the M 7.1,4 September 2010 Darfield earthquake. However, it caused severe damage in the downtown Christchurch. Such a circumstance points out the importance of an aftershock sequence in seismic hazard evaluation and suggests the re-evaluation of a seismic hazard immediately after a large earthquake occurrence. For this purpose, we propose a probabilistic seismic hazard assessment (PSHA), which takes the disturbance of a short-term seismicity rate into account and can be easily applied in comparison with the classical PSHA. In our approach, the treatment of the background seismicity rate is the same as in the zoneless approach, which considers a bandwidth function as a smoothing Kernel in neighboring region of earthquakes. The rate-and-state friction model imparted by the Coulomb stress change of large earthquakes is used to calculate the fault-interaction-based disturbance in seismicity rate for PSHA. We apply this approach to evaluate the seismic hazard in Christchurch after the occurrence of the M 7.1, 4 September 2010 Darfield earthquake. Results show an increase of seismic hazards due to the stress increase in the region around the rupture plane, which extended to Christchurch. This provides a suitable basis for the application of a time-dependent PSHA using updating earthquake information.
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U2 - 10.3319/TAO.2011.09.23.02(T)
DO - 10.3319/TAO.2011.09.23.02(T)
M3 - Article
AN - SCOPUS:84859389273
SN - 1017-0839
VL - 23
SP - 231
EP - 236
JO - Terrestrial, Atmospheric and Oceanic Sciences
JF - Terrestrial, Atmospheric and Oceanic Sciences
IS - 2
ER -