摘要
Since the Earth outer core is liquid, the shear waves that are generated by alarge earthquake and traveling to the core (ScS) will totally reflect with strong seismic ener-gy. It is interesting to note that one large aftershock (Mw = 6. 0) of the 2008 Sichuan earth-quake (Mw = 7. 9) in China just occurred when the ScS phase returned around 15. 5 minuteslater after the mainshock occurred. The estimated peak dynamic stress (~3. 3 kPa) of theScS amplitude was reaching to the generally lower bound for capable of triggering earth-quakes. Both the temporal correlation between the aftershock occurrence and the ScS arrivalas well as the large enough dynamic stress suggest that the largest aftershock might be trig-gered dynamically by the ScS waves. Further statistic examinations of 24 major earthquakes(Mw>7. 5) since 2000 show some large aftershocks (Mw>5. 0) also coincidentally occurredaround the ScS phase arrived. Those observations imply that aftershocks might likely betriggered dynamically by the ScS phases, and thus a temporal warning for potentially de-structive aftershocks might be considered in the future great earthquakes.