How Continents Move Practice Questions

Review the following concepts: How Continents Move Study Guide

Practice Questions

1. The discovery of how continents move came from geological studies of what area?

a. of the Rocky Mountains

b. of the Himalayan Mountains

c. of the Atlantic Ocean

d. of the Indian Ocean

2. Seafloor spreading is the term used for what process?

a. the creation of new sea floor at midocean ridges

b. the creation of new sea floor as continental edges erode

c. the lifting up of the sea floor from the under lying mantle

d. the lifting up of the sea floor near the continents

3. Earth's magnetic field plays an important role in the theory of how continents move, because of which of the following facts?

a. Molten magma comes up magnetized from the asthenosphere.

b. Earth's field switches from normal to reversed and back again.

c. The direction for the spreading of the sea floor follows the magnetic field.

d. Continents act to create a magnetic tape in the mountains.

4. If the coasts of Africa and North Carolina, United States, are about 5,000 kilometers apart and have been spreading apart at a constant rate of 2.8 centimeters per year, how long ago were they joined as part of the same continent?

a. 14 million years ago

b. 18 million years ago

c. 140 million years ago

d. 180 million years ago

5. Which is NOT true?

a. The lithosphere gets thicker as it moves away from a mid-ocean ridge.

b. As magma turns to rock, it records Earth's magnetic field.

c. The mid-ocean ridge is a bulge made by the two sides of the ocean moving together.

d. Alfred Wegener developed the theory of drifting continents from looking at the shapes of South America and Africa.

6. Ocean floor dives downward and disappears into the mantle at what points?

a. subduction zones

b. mid-ocean ridges

c. continental coasts

d. tectonic rifts

7. Because the Pacific Ocean is shrinking in size, which of the following can we say about the Pacific's geology that is relevant to the shrinking?

a. Its mid-ocean ridges are stronger than its subduction zones.

b. Its subduction zones are further away from its ridges than in the Atlantic Ocean.

c. Its subduction zones are closer to its ridges than in the Atlantic Ocean.

d. Its subduction zones are stronger than its mid-ocean ridges.

8. In a subduction zone, which is NOT true?

a. The slab heads toward the mantle.

b. The subducting slab is very dense.

c. Asthenosphere becomes lithosphere.

d. The slab is thicker than it was at the midocean ridge.

9. The deep ocean trenches are found where?

a. mid-ocean ridges

b. volcanic vents

c. subduction zones

d. sites of warmest waters

10. The subducting slab essentially ends its journey at what depth?

a. 10 meters

b. 10 kilometers

c. 100 meters

d. 100 kilometers

11. In the theory of plate tectonics, the net amount of subduction equals the net amount of seafloor spreading, because of which of the following facts?

a. The 5,000 K temperature of Earth's core makes this fact so.

b. Earth's surface must remain the same size and thus in balance.

c. Heat comes up, not down, from the deeper mantle.

d. Transform margins are available to make up any difference.

12. Which type of margin initially begins under a continent?

a. convergent margin

b. transform margin

c. subduction margin

d. divergent margin

13. Which is NOT true about the Earth's plates?

a. Interactions occur at the edges.

b. Some plates have both subduction zones and seafloor spreading.

c. The edge of South America cannot be the edge of a plate.

d. The edge of the plate that includes North America is in the middle of the Atlantic Ocean.

14. Which type of margin causes earthquakes in California?

a. convergent margin

b. transform margin

c. subduction margin

d. divergent margin

15. In the analogy between plate tectonics and either the eggshell of an egg or the rafts of plywood on water, which is true?

a. The rafts are like the plates.

b. The plate edges are the meetings of eggshell and egg.

c. The cracked eggshell is more dynamic than Earth's plates.

d. The eggshell is like the continents.

 Answers