Plate Tectonics, Earthquakes, & Volcanoes

According to Wegener’s hypothesis of continental drift,

• Earth’s surface is made up of seven major landmasses.

• the continents do not move.

• Earth is slowly cooling and shrinking.

• the continents were once joined together in a single landmass.

What is Pangaea?

• the name of a German scientist

• the name of the supercontinent that existed millions of years ago

• another name for continental drift

• the name of an ancient fossil

In sea-floor spreading, molten material rises from the mantle and erupts

• along the edges of all the continents.

• along mid-ocean ridges.

• in deep-ocean trenches.

• at the north and south poles.

Most geologists think that the movement of Earth’s plates is caused by

• conduction.

• earthquakes.

• convection currents in the mantle.

• Earth’s magnetic field.

The geological theory that states that pieces of Earth’s lithosphere are in constant, slow motion is the theory of ________.

• subduction

• plate tectonics

• deep-ocean trenches

• sea-floor spreading

A place where two plates slip past each other, moving in opposite directions, is known as a ________.

• transform boundary

• divergent boundary

• convergent boundary

• rift valley

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

• mid-ocean ridge

• deep-ocean trench

• rift valley

• mountain range

Along a divergent boundary, two plates slip past each other, moving in opposite directions.

• True

• False

The point beneath Earth’s surface where rock breaks under stress and triggers an earthquake is called the

• syncline

• footwall

• epicenter

• focus

The type of seismic waves that arrive at the surface first and move by compressing and expanding the ground like an accordion are called

• S waves.

• P waves.

• Surface waves.

• Mercalli waves.