Terr. Atmos. Ocean. Sci., Vol. 19, No. 6, 697-703, December 2008 |
doi: 10.3319/TAO.2008.19.6.697(PT) |

Po-Fei Chen^{1},
Andrew V. Newman^{2}, Tso-Ren Wu^{3,*},
Ching-Ching Lin^{1 }

^{1}Department of Earth Sciences,

^{2}Georgia

^{3}Institute of Hydrological Sciences,

**Abstract**

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 M_{L} to seismic moment (M_{0}),
we test the well-defined energy to moment ratio (E/M_{0})
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)