Spatiotemporial seismicity pattern of the Taiwan orogen

Abstract. We investigate the temporal and spatial seismicity patterns prior to eight M > 6 events nucleating in different region of Taiwan through region-time-length algorithm and analysis of self-organizing spinodal model. Our results reveal that the spatiotemporial seismicity variations during the preparation process of impending earthquakes would display distinctive pattern corresponding to the tectonic setting. Q-type events occur in southern Taiwan and experience seismic quiescence stage prior to the mainshock. Seismicity decrease of 2.5 < M < 4.5 events around the high b-value southern Central Range, which contributes to accumulate the tectonic stress for preparing the occurrence of the Q-type event. On the other hand, A-type events occur in central Taiwan and experience seismic activation stage prior to the mainshock, which nucleated on the edge of the seismic activation area. We should pay attention when accelerating seismicity of 3 < M < 5 events appears within the low b-value area, which would promote the nucleation process of the A-type event.