UNDERSTANDING A GROUND SHEAR DISPLACEMENT PLOT: Trajectories for displacement of rigid ground (blue) and compliant (red) ground are plotted above for a 2° slope subjected to the Newhall record. The maximum displacement occurs upslope to the north (~18cm). Downslope ratcheting of the ground ultimately drives the final displacements in the opposite direction (6 and 15 cm). The trajectories map the position of the ground during earthquake shaking. (Note: The modeled flexible displaced ground is 15m tall with Vs= 100m/s, Tground = 1.26 s.). Below is a similar ground displacement plot.