Science 3.2 Test Review

Most tectonic plates have both oceanic and continental crust. How are oceanic and continental crust different?

• Oceanic crust is thinner and lighter than continental crust.

• Oceanic crust is thicker and lighter than continental crust.

• Oceanic crust in thinner and denser than continental crust.

• Oceanic crust is thicker and denser than continental crust.

Most divergent plate boundaries lie under the world's oceans. Which of the following is a process that occurs at divergent boundaries?

• magnetic reversals

• recycling of crustal material

• formation of continental crust

• formation of mid-ocean ridges

Which of the following describes magma?

• solid rock

• molten rock

• volcanic ash

• volcanic cone

During the year 2003, the number of earthquakes that occurred was higher than usual. The map below shows the locations of some of these earthquakes. Why do the dots on the map tend to form a long curving line in the western part of the Pacific Ocean?

• This part of the ocean has a high rate of hurricanes and typhoons.

• That part of the ocean is directly above the boundaries between tectonic plates.

• An increase in the number of tsunamis in the Pacific led to an increase in the number of earthquakes.

• There is pressure on the sea floor due to the weight of water of the Pacific Ocean.

Most divergent plate boundaries lie under the world's oceans. Which of the following is a process that occurs at divergent boundaries?

• subduction of old crust

• formation of new crust

• formation of new crust

• continental collisions occur

Which of the following events can produce an earthquake?

• the force of tsunamis in the oceans

• movement of tectonic plates along a fault

• a sudden release of energy from the mantle

• the violent shaking of sections of the lithosphere

The figure below shows the process of subduction. What can you conclude from this figure?

• The two tectonic plates are sliding past each other horizontally along Earth's surface.

• The two tectonic plates are moving apart to create a mid-ocean ridge on the sea floor.

• two tectonic plates are diverging, causing the continental plate to buckle and form mountains.

• The two tectonic plates are converging so that a mountain range forms on the continent.

Earth's mantle s made of a dense thick material that allows movement of crustal plates. Crustal plate movement occurs because the mantle flows as a result of uneven heating inside the mantle. _______________ are created by very hot material deep in the mantle rising, then cooling, sinking again, and then heating again and then repeating the cycle.

• magma flows

• magma currents

• convection waves

• convection currents

The continental crust is _________ than the oceanic crust and seems to "float" on the mantle.

• thinner

• younger

• less dense

• mostly basalt

Which of these is the thickest layer of the Earth?

• crust

• mantle

• outer core

• inner core