Exercise 3 solution

Profile, from the coast outwards:
1. Continental shelf: shallow (0 to about 130 m), gently sloping.
2. Shelf break: the edge where the slope steepens.
3. Continental slope: steep descent to roughly 2,000 m or more.
4. Continental rise: a gentle apron of sediment at the foot of the slope.
5. Abyssal plain: flat floor at 3,000 to 6,000 m.
6. Trench: a narrow groove plunging to 6,000 to 11,000 m at a plate boundary.

Flattest: the abyssal plain. Steepest: the continental slope over a wide scale, and the walls of the trench locally.