When two tectonic plates collide, the oceanic crust usually subducts beneath the continental crust because it is_________.

• a. denser than continental crust

• b. less dense than continental crust

• c. thicker than continental crust

• d. thinner than continental crust

If you will visit a place in the Pacific known to be along converging plates, which of these should you not expect to see?

• a. active volcanoes

• b. mountain ranges

• c. rift valleys

• d. volcanic islands

You are an oceanographer and want to map the ocean floor on the east coast of the Philippines. As you do your study, you noticed that there is a portion of the ocean floor which is relatively much deeper than the rest. What most likely is that deeper part?

• a. linear sea

• b. oceanic ridge

• c. rift valley

• d. trench

What do you expect to find at a mid-ocean ridge?

• a. relatively young rocks

• b. reverse fault

• c. thick accumulation of sediments

• d. very ancient rocks

Crustal Plate A is moving away from Crustal Plate B. What is the expected average rate of change in position between A and B?

• a. a few centimeters per year

• b. a few meters per month

• c. a few millimeters per century

• d. a few millimeters per day

Which plate boundary is formed between the Philippine Plate and the Eurasian Plate?

• a. convergent

• b. divergent

• c. reverse fault

• d. transform fault

Which of these is FALSE about crustal plates:

• a. have the same thickness everywhere

• b. include the crust and upper mantle

• c. thickest in the mountain region

• d. vary in thickness

In 1912, Alfred Wegener proposed a theory that the Earth is once a single landmass. What is the name of the Mesozoic supercontinent that consisted of all of the present continents?

• a. Eurasia

• b. Laurasia

• c. Pangaea

• d. Gondwanaland

Who were the two scientists who proposed the theory of seafloor spreading in the early 1960s?

• a. Charles Darwin and James Hutton

• b. Harry Hess and Robert Dietz

• c. John Butler and Arthur Smite

• d. F. Vine and D. Mathews

Which of the following diagrams best illustrates the convection occurring in the mantle?

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