Submarine canyons: a. are found cutting the abyssal plains. b. are found cutting the mid-ocean ridge systems forming large fracture zones. c. are found cutting across continental shelves and slopes. d. all of the above. Mid-ocean ridges are steeper and less broad than rises because: a. the rocks of the mid-ocean ridges are composed of more dense mineral than the rises. b. the rocks of the mid-ocean ridges are composed of less dense mineral than the rises. c. The seafloor spreading rate of ridges are faster than rises causing the oceanic crust to subside closer to the ridge axis. d. The seafloor spreading rate of ridges are slower than rises causing the oceanic crust to subside closer to the ridge axis. e. Every ridge is composed of continental crust. Fracture zones (not oceanic transform boundaries) are: a. seismically active (have earthquakes). b. are aseismic (no earthquakes). A passive continental margin: a. is characterized by earthquakes. b. sheds more sediment than [active] margins. c. is typically volcanically active d. all of the above (choices a, b, c) e. none of the above is correct.