Based on 568 typical loess landslides induced by the 1920 Haiyuan Ms8 1/2 earthquake,the study explores the kinematic characteristics of loess seismic landslides from three aspects:di-rectivity,long run-out slip characteristics,and flow-slide characteristics.The main conclusions are as follows:(1)The main sliding directions of landslides induced by the Haiyuan earthquake are concentrated in two intervals:60°-90° and 270°-300°,which are consistent with the domi-nant slope direction ranges of 50°-90° and 255°-290°,respectively,demonstrating a distinct characteristic of being along the slope direction.(2)Landslides whose main sliding direction is parallel to or intersects with the strike of a seismogenic fault at a small angle(0°-30°)account for 41.9％,and the sliding direction is substantially affected by the fault dislocation direction.(3)Landslides are densely distributed on the facing slope,the number of which is 1.98 times that on the back slope,demonstrating typical facing slope characteristics.(4)A correlation exists between the maximum horizontal distance of a landslide and the slope height.Landslides are densely developed at a slope height of 30-120 m,and the equivalent friction coefficients of land-slides are all less than 0.4,showing typical run-out slip characteristics.(5)Landslides with an equivalent friction coefficient of less than 0.17 account for 70.95％of the 568 landslides,revealing flow-slide characteristics.As an important supplement to the research results on the development characteristics of loess earthquake landslides,the conclusions have a certain reference value for further research on the disaster mechanism and risk assessment of loess earthquake landslides.
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