Pearson Chapter 4 - Plate Tectonics

Who was Alfred Wegener?

• A German scientist who created the theory of continental drift.

• A German scientist who created the theory of seafloor spreading.

• A German scientist who created the theory of plate tectonics.

• A French scientist who created the theory of continental drift.

What is the theory of continental drift?

• Wegener's hypothesis that the continents were once separated and have since then joined together.

• Wegener's hypothesis that all the continents were once joined together in a single landmass and have since drifted apart.

• Bill Nye's hypothesis that all the continents were once joined together in a single landmass and have since drifted apart.

• A theory in which the continents drift

What was Pangaea?

• The supercontinent that Wegener hypothesized the continents were once joined in

• Wegener's breakfast: Pancakes and eggs

• A supercontinent that existed 400 million years ago

• A supercontinent that Tharp hypothesized the continents weren't once joined in

Select the pieces of evidence that support the theory of continental drift.

• Fossils of animals that could not swim were found on different landmasses separated by continents. When put together, the locations of the fossils created a band.

• Mountain ranges, coal deposits, and glacial sediment deposits matched up on different continents.

• The coastlines of South America and Africa fit together almost perfectly.

• Pillow-shaped rocks were found on ocean floors, indicating molten material must have cooled quickly.

• Tropical plant fossils were found on an Arctic island. This indicates that the landmass must have moved away from the equator, therefore becoming cooler and not able to support tropical plant life.

Why was Wegener's hypothesis rejected by most scientists?

• Wegener did not have enough evidence to support his theory.

• The scientists were being mean.

• Wegener couldn't provide a mechanism as to how the continents plowed through the ocean.

• It wasn't good enough.

What are mid-ocean ridges?

• Continental mountain ranges at which land spreading occurs.

• Ridges in the middle of the ocean

• Underwater mountain ranges at which subduction occurs.

• Long, underwater mountain ranges at which seafloor spreading occurs.

What is sonar?

• Sound Opaque Nothing And Readiness

• A device that uses light to measure the distance to an object; this was used to discover mid-ocean ridges

• Futuristic technology

• A device that uses sound waves to measure the distance to an object; this was used to discover mid-ocean ridges.

Which two statements about seafloor spreading are true?

• An ocean with many ridges and few trenches will grow

• An ocean with many ridges and many trenches will grow.

• An ocean with few ridges and many trenches will shrink.

• An ocean with few ridges and few trenches will shrink.

What is the process of seafloor spreading?

• When the seafloor spreads

• When mid-ocean ridges make the Earth bigger

• When mid-ocean ridges continually add new material to the ocean floor

• When volcanoes continually add new material to continental crust

Choose the evidence that supports the process of seafloor spreading.

• Pillow rocks on the ocean floor indicate that molten material cooled quickly.

• Identical magnetic stripes created by reversals of the magnetic field indicate both sides of ridges spread at the same rate.

• The coastlines of South America and Africa fit together almost perfectly.

• Drilling samples taken progressively further from mid-ocean ridges are progressively older the farther from the ridge.

• Mountain ranges, coal deposits, and glacial sediment deposits on different continents line up.