643815.fig.006a
(a) Flat floor
643815.fig.006b
(b) Downward step
643815.fig.006c
(c) Upward step
643815.fig.006d
(d) Trench
643815.fig.006e
(e) Downward slope
643815.fig.006f
(f) Upward slope
Figure 6: How to classify slopes, steps, and trenches. Mathematical algorithms are shown.