Figure 7
A line graph shows the amplitude in millimeters on the vertical axis ranging from negative 4 to positive 4 millimeters. The horizontal axis represents the location in kilometers, spanning from 280 to 400 kilometers. The graph illustrates the longitudinal irregularity of the left track, with the amplitude fluctuating around the zero mark, indicating variations in the track's surface.Left-track longitudinal irregularity. Source(s): Author's own work