Abstract: Fault zone trapped waves (FZT Ws) mainly travel along the low velocity cracked fault zone (FZ) and contain significant information about its internal structure, so their wave field characteristics are very important for FZ structure inversion. Previous resear-ches mostly simulated the FZTWs on the vertical fault structures and would bias from the real FZ that were normally inclined. In this paper, we implemented simulations on selected models with a vertical or inclined FZ and compared their wave fields in both time and fre-quency domains. The results show that wave field on the surface has significant different amplitude distribution across both sides of the vertical and inclined faults when low velocity fault zone exist and especially when the two fault walls have velocity contrasts. In addi-tion, the results also indicate that the trapped waves can be created above the FZ for both the vertical and inclined fault with similar amplitude characteristics. However, their polar izations on the cross fault plane would be variant. The polarities trend to be single direc tion for vertical fault but fork to multiple directions for inclined fault. The simulation re-sults can help to invert real FZ structures, and also enhance the knowledge on near fault strong ground motions. .

Key words: Fault zone trapped waves, Spectral element method, Inclined fault, Wave field characteristics