3 Written questions
3 Multiple choice questions
- an undersea mountain chain that is part of a long system of mountains that winds beneath Earth's oceans.
- Several types of evidence supported the theory of sea floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.
- deep underwater canyons
2 True/False questions
What happens at deep-ocean trenches? → In a process taking tens of millions of years, part of the ocean floor sinks back into the mantle at deep-ocean trenches.
sonar → a device that bounces sound waves off underwater objects and then records the echoes of these sound waves.