Terr. Atmos. Ocean. Sci., Vol. 19, No. 6, 743-749, December 2008

doi: 10.3319/TAO.2008.19.6.743(PT)

Precursory Seismic Activation of the Pingtung ( Taiwan ) Offshore Doublet Earthquakes on 26 December 2006: A Pattern Informatics Analysis


Yi-Hsuan Wu1, Chien-chih Chen1,* and John B. Rundle2


1 Department of Earth Sciences and Graduate Institute of Geophysics , National   Central University , Jhongli, Taoyuan , Taiwan 320, ROC

2 Center for Computational Sci. & Eng., UC Davis, One Shields Ave., Davis, CA, 95616



We report the retrospective analyses of frequency-magnitude distributions (FMD) and pattern informatics (PI) for the Pingtung offshore doublet earthquakes having magnitudes 6.7 and 6.4. The frequency-magnitude distributions of earthquakes that occurred in the study area preceding the Pingtung doublets demonstrate the activation of moderate events since March 2004, about three years before the Pingtung doublets. In addition, in the calculated PI map, the hypocentral area of the doublets exhibits the signatures of anomalous activity associated with the precursory seismic activation. Our study therefore suggests that, by inspecting temporal variations in the frequency-magnitude distributions of earthquakes, together with the hotspot locations with intense seismicity changes in the PI map, it is possible to shed light on the relevant preparation processes of the forthcoming large earthquakes. 

Keywords: Pattern informatics, Seismicity changes, Precursory phenomena, Pingtung offshore doublet earthquakes

Citation: Wu, Y. H., C. C. Chen, and J. B. Rundle, 2008: Precursory seismic activation of the Pingtung (Taiwan) offshore doublet earthquakes on 26 December 2006: A pattern informatics analysis. Terr. Atmos. Ocean. Sci., 19, 743-749, doi: 10.3319/TAO.2008.19.6.743(PT)