Reviewer 1.3 Science 10

Scientists believe that the movement of tectonic plates is primarily driven by convection currents in the mantle. Which of the following best describes how these currents work?

• Hot material rises, cools, then sinks in a continuous cycle.

• Plates are pushed apart by ocean tides.

• Earth's rotation spins the plates around.

• Wind pressure on the surface pushes plates.

The Philippine Plate is moving toward the Eurasian Plate. This is mainly caused by:

• Lunar gravitational pull

• Mantle convection currents

• Differences in salinity of oceans

• Erosion of coastal areas

Which of the following BEST explains why oceanic crust is denser than continental crust?

• Oceanic crust is made of basalt, which is denser than granite.

• Continental crust is older than oceanic crust.

• Oceanic crust is formed from cooled magma in mountains.

• Continental crust has more water content.

The Himalayas were formed when the Indian Plate collided with the Eurasian Plate. This is an example of movement caused by:

• Ridge push

• Slab pull

• Convection currents

• All of the above

Slab pull happens when:

• Plates slide past each other causing earthquakes.

• A dense oceanic plate sinks into the mantle pulling the rest of the plate.

• Magma erupts and pushes plates apart.

• Earth's magnetic field attracts the plates.

Ridge push occurs at:

• Subduction zones

• Mid-ocean ridges

• Volcano summits

• Earthquake epicenters

In the diagram of mantle convection below, what happens to magma as it cools?

• It sinks toward the core.

• It rises toward the crust.

• It forms new ocean trenches.

• It turns into continental crust.

Why is the Pacific Plate moving northwest?

• Ocean currents drag it.

• Gravity pulls subducting edges downward.

• Winds push the surface.

• The Moon pulls it.

Which force contributes MOST to the sinking of an oceanic plate beneath a continental plate?

• Ridge push

• Slab pull

• Earthquake force

• Tidal force

If mantle convection stops, what will MOST likely happen to plate movement?

• Plates will continue moving at the same speed.

• Plate movement will slow down or stop.

• Plates will move faster due to gravity.

• No effect will occur on plates.