Natural Hazards and Earth System Sciences (May 2013)

Time-dependent probabilistic seismic hazard assessment and its application to Hualien City, Taiwan

  • C.-H. Chan,
  • Y.-M. Wu,
  • C.-T. Cheng,
  • P.-S. Lin,
  • Y.-C. Wu

DOI
https://doi.org/10.5194/nhess-13-1143-2013
Journal volume & issue
Vol. 13, no. 5
pp. 1143 – 1158

Abstract

Read online

Here, we propose a time-dependent probabilistic seismic hazard assessment and apply it to Hualien City, Taiwan. A declustering catalog from 1940 to 2005 was used to build up a long-term seismicity rate model using a smoothing Kernel function. We also evaluated short-term seismicity rate perturbations according to the rate-and-state friction model, and the Coulomb stress changes imparted by earthquakes from 2006 to 2010. We assessed both long-term and short-term probabilistic seismic hazards by considering ground motion prediction equations for crustal and subduction earthquakes. The long-term seismic hazard in Hualien City gave a PGA (peak ground acceleration) of 0.46 g for the 2.1‰ annual exceedance probability. The result is similar to the levels determined in previous studies. Seismic hazards were significantly elevated following the 2007 ML =5.8 earthquake that occurred approximately 10 km from Hualien City. This work presents an assessment of a suitable mechanism for time-dependent probabilistic seismic hazard determinations using an updated earthquake catalog. Using minor model assumptions, our approach provides a suitable basis for rapid re-evaluations and will benefit decision-makers and public officials regarding seismic hazard mitigation.