Earth Science Review

Scientists estimate that the Earth is approximately ____ years old. 

• 4,600
• 4.6 million
• 46 million
• 4.6 billion

The ______ of the Earth is mostly made up of iron and contains roughly one-third of the Earth's mass. 

• crust
• mantle
• core
• lithosphere

The tectonic plates move on the ___________ -- the soft, upper layer of the mantle. 

• lithosphere
• asthenosphere
• mesosphere
• ionosphere

Which scientist described the theory of continental drift?

• Alfred Wegener
• Charles Darwin
• James Hutton
• Charles Lyell

____________ is when hot rock from deep within the Earth rises, but cooler rock sinks. 

• Ridge push
• Convection
• Slab pull
• Seismic shift

_________ is the sudden return of elastically deformed rock to its undeformed shape. 

• Plastic deformation
• Elastic deformation
• Elastic rebound
• Plate shift

Scientists use a(n) __________ to record vibrations in the ground and determines the location and strength of an earthquake. 

• seismograph
• seismogram
• S-P graph
• compass

The _______ is the point along a fault at which the first motion of an earthquake occurs. 

• epicenter
• focus

True or False? The gap hypothesis states that a major earthquake is more likely to occur along the part of an active fault where many earthquakes have occurred recently. 

• True
• False

A 2.0 earthquake on the Richter Magnitude Scale

• would cause widespread damage. 
• causes damage at the epicenter. 
• could be felt by most people at the epicenter. 
• would only be detected by a seismograph.