Terr. Atmos. Ocean. Sci., Vol. 19, No. 6, 697-703, December 2008

doi: 10.3319/TAO.2008.19.6.697(PT)

Earthquake Probabilities and Energy Characteristics of Seismicity offshore Southwest Taiwan


Po-Fei Chen1, Andrew V. Newman2, Tso-Ren Wu3,*, Ching-Ching Lin1


1Department of Earth Sciences, National Central University

2Georgia Institute of Technology

3Institute of Hydrological Sciences, National Central University




     We characterize fault geometries for moderate and large earthquakes in and offshore southwest (SW) Taiwan. Stress orientation estimates suggest that the first shock of the Pingtung earthquake may be characterized by slab flexure. Aregion of predominately normal-faulting earthquakes is also defined. Using the maximum-likelihood Gutenberg-Richter relation, we find that the repeat times for magnitude, M ≥6.5 and M ≥7.0 earthquakes are approximately 30 and 80 years, respectively. By assuming a Gaussian probability distribution with a standard deviation of 0.4 the recurrence time, we estimate a 50% probability of an M≥ 6.5 earthquake recurring in the next 30 years, while only a 20% probability of an M≥ 7.0 in the next 50 years. To test the empirical relation that is currently being used to convert ML to seismic moment (M0), we test the well-defined energy to moment ratio (E/M0) for the region. We additionally utilize this method to identify the lack of slow-source earthquakes in several recent offshore events in Taiwan.


Keywords: Taiwan seismicity, Gutenberg-Richter relation, Earthquake probability, Tsunami earthquake

Citation: Chen, P. F., A. V. Newman, T. R. Wu, and C. C. Lin, 2008: Earthquake probabilities and energy characteristics of seismicity offshore southwest Taiwan. Terr. Atmos. Ocean. Sci., 19, 697-703, doi: 10.3319/TAO.2008.19.6.697(PT)