The lithosphere is:

Earthquakes occur frequently at

All of the above.

Volcanic activity is abundant at all of the following except

Volcanic activity is found at all of the above locations.

The asthenosphere is

a layer of low rigidity that separates the rigid lithosphere from the rigid mantle.

A seamount forms when

a volcano is eroded by waves and sinks as it becomes denser with time.

The Himalayan mountain system formed when

an ocean that once separated India and Asia closed by subduction.

Most of Earth's volcanic and earthquake activity occurs

at the edges of lithosphere plates.

The lithosphere is:

composed of the entire crust and the uppermost mantle.

In the tectonic cycle, new lithosphere forms at _____________ and is consumed at _____________.

ocean ridges; subduction zones

The eastern edge of the North American plate is

the Mid-Atlantic Ridge because that is where sea-floor spreading is taking place.

The eastern edge of the North American continent is not the same as the eastern boundary of the North American plate. The eastern edge of the North American continent is

the edge of the continental shelf because that is where continental crust ends and oceanic crust begins.

The only type of plate boundary at which there is no vertical transfer of material between the lithosphere and asthenosphere is a

transform fault.

Volcanic arcs form above subduction zones

wherever oceanic lithosphere is subducted.