Plate Tectonics Fast and Curious

The graph shows the average number of daily earthquakes in Japan and East Asia from 1991 to 2007.

Which of the following is the likeliest explanation for the frequency of earthquakes shown on the graph?

• a. There is a constant release of magma from all the volcanoes in the area.

• b. It is located just off the mid-ocean ridge where new rock material is constantly being formed.

• c. There are many tectonic plate boundaries in this area that are constantly moving.

• d. It sits on the Pacific Ocean where large storms are constantly bombarding the coast.

The map shows the location of continents and mid-ocean ridges on Earth. The mid-ocean ridges can be used to provide evidence of past plate motions.

Which of the following best explains how tectonic plates move?

• a. The forces of tension, compression, and shearing cause the rock that makes up plates to stretch, squeeze, or break apart, and these changes in the shape of the plates cause them to quickly move.

• b. The force of uplifting pushes up large sections of Earth’s crust, which cause the plates to quickly shift and move.

• c. Hot spots, where magma erupts through Earth’s crust, add new rock to plate boundaries, which cause the plates to slowly shift and move.

• d. Sea-floor spreading at mid-ocean ridges and subduction at deep-ocean trenches work together to slowly move the plates.

Olivia became interested in the fossil evidence that Wegener used to form his hypothesis of continental drift. How did fossils show that the continents were once joined together?

• a. Animal fossils such as the mesosaurus were found on one continent.

• b. Scientists found examples of different kinds of fossils on some continents.

• c. Plant fossils of the same kind of fernlike plants were found on five continents.

• d. Freshwater animal fossils were found in the nearby oceans.

A collision between two pieces of continental crust at a converging boundary produces a

• a. mid-ocean ridge.

• b. deep-ocean trench.

• c. rift valley.

• d. mountain range.

How do moving plates change Earth's crust?

• a. They add new crust at mid-ocean ridges.

• b. They cause oceanic crust to be destroyed at deep-sea trenches.

• c. They squeeze continental crust into mountains and pull the crust apart at rift valleys.

• d. All of the above

Plate boundaries behave in different ways, depending on the location and their motion. What are two possible outcomes for a divergent boundary?

• a. rift valley and mid-ocean ridge

• b. deep ocean trenches and earthquakes

• c. mountain building and subduction

• d. volcanoes and seamounts

What does the theory of Continental Drift explain?

• Ocean currents move continents around the planet

• Convection works deep within the asthenosphere

• Mid-ocean ridges force tectonic plates to move

• Continents were once together and slowly drifted to where they are today

Tectonic plates are made of?

• The mantle

• Continental and oceanic lithosphere

• The outer core

• The mesosphere

Where are the youngest rocks on Earth found?

• Along mid-ocean ridges

• Along transform boundaries

• On the edges of the continents

• Near ocean trenches

Who was the scientist who proposed the theory of continental drift?

• Alfred Powell

• Harry Hess

• Alfred Wegener

• Ernest Rutherford