Abstract: We proposed an annual sliding velocity ratio to annalyse cross-fault deformation observation data. This can be used to eliminate gross error, normal annual dynamic observation and linear trend component, and to highlight the abnormal change information. We use the method to analyze fault activity level in a region by synthesis under a unified dimensionless datum. As an example, we calculated anomalies of annual sliding velocity ratio of the cross-fault deformation observation in Sichuan before the Lushan M_S7.0 earthquake on April 20, 2013. The results show that the method has better feasibility and practicability in the study of earthquake analysis and prediction.

Key words: Annual sliding velocity ratio, Cross-fault deformation observation, The 2013 Lushan M_S7.0 earthquake