Earth's Layers and Tectonic Plates

Which layer is the most diverse, containing silica, oxygen, aluminum, and magnesium?

• the crust

• the mantle

• the inner core

• the outer core

At what layer of Earth do convection currents occur?

• Crust

• Lithosphere

• Asthenosphere

• Core

What layers of Earth make up the lithosphere?

• The crust and lower mantle

• Thecrust and upper mantle

• The continental crust and oceanic crust

• The upper and lower mantle

The multidirectional movement of tectonic plates causes many geological events such as volcanoes, earthquakes, mountain building, and the formation of new ocean basins. What is the source of this movement that causes these events?

• excess heat from the Sun that melts the crust to form lava and magma, which move over the plates

• Earth's rotation on its axis, which forces the plates to move across the Earth's surface

• convection currents created by heat from radioactive decay inside Earth

• the gravitational force of the Sun pulling on Earth's crust

The picture below shows a model of Earth's layers. Use the picture to answer any questions that follow. Which

is Layer 1?

• the lithosphere, where liquid magma convects in circular patterns

• the inner core, which is a solid, dense layer made mostly of iron

• the crust, which is liquid and composed mainly of nickel and iron

• the outer core, which is a rigid, loose layer with low temperatures

Composed mainly of nickel and iron, this layer is liquid and is rotating.

• Layer 1

• Layer 2

• Layer 3

• Layer 4

What process is illustrated by the area labeled “A” in the figure above?

• Seafloor spreading

• Continental volcanism

• Rifting

• Subduction

The picture below shows a hard-boiled egg, where the shell is a model for the lithosphere of Earth. Use the picture to answer any questions that follow. What do the cracks in the egg shell represent?

• mountain ranges in the northern hemisphere

• holes in the ozone layer of the atmosphere

• fault lines made by moving tectonic plates

• the boundaries between land and ocean

The model below shows how mountains build on Earth's crust through the movement of tectonic plates X and Y. When does this type of mountain building occur?

• when continental plates X and Y, having different densities, diverge and deposit soil in large mounds

• when continental plates X and Y, having similar densities, converge and push Earth's crust upward

• when continental plate X and oceanic plate Y, having different densities, collide

• when continental plate X and oceanic plate Y, having similar densities, separate

Which statement BEST explains why the risk of earthquakes is very high along the California coast, but very low along the Florida coast?

• Earthquakes move from west to east due to Earth’s rotation, so they do not reach the east coast if the continent.

• The North American plate is moving toward the west, so there is much more stress at the western boundary.

• The mountains near the west coast reflect the energy of earthquakes, but the mountains in the east are smaller and do not.

• There is a plate boundary beneath the west coast of the continent, but the plate extends beyond