Chapter Questions
Describe the main differences between oceans and continents.
Sketch a cross section of the central rift valley in the Mid-Oceanic Ridge.
Describe the dimensions of the Mid-Oceanic Ridge system.
Explain why the Mid- Oceanic Ridge is topographically elevated above the surrounding ocean floor. Why does its elevation gradually decrease away from the ridge axis?
Explain the origin of the rift valley in the center of the Mid-Oceanic Ridge.
Why are the abyssal plains characterized by such low relief?
Sketch a cross section of oceanic crust from the seafloor. Label, describe, and indicate the approximate thickness of each layer.
Describe the two main types of seafloor sediment. What is the origin of each type?
Compare the ages of oceanic crust with the ages of continental rocks. Why are they so different?
Sketch a cross section of both an active continental margin and a passive continental margin. Label the features of each. Give approximate depths below sea level of each of the features.
Explain how a continental shelf-slope-rise complex forms on a continental margin.
Why does an active continental margin typically have a steeper continental slope than a passive margin?
Why do oceanic islands sink after they form?