What part of the rocks did scientists study to determine that the Earth's magnetic field had reversed several times. 

• the core
• iron-bearing minerals
• dirt
• asthenosphere

What uses sound waves to calculate distance?

• tectonic plates
• SLR
• Sonar
• GBX

What measures the strength of a magnetic field?

• A large magnet
• a magnetometer
• HGT
• FHV

What uses pulses of light to measure distance?

• SLR
• FBH
• DSL
• Ipod

What does a GPS do?

• use sound waves to calculate distance?
• use light to calculate distance
• a network of satellites used to determine locations on Earth
• measure how far frogs jump

What does Pangea mean?

• "all land"
• "old land"
• "big land"
• "make believe land"

The theory that describes Earth's crust and upper mantle as being broken into sections is called...

• awesome
• plate tectonics
• pangea
• a theory

What is the lithosphere?

• a solid, but plastic layer found in the upper mantle
• the core of the Earth
• the crust, and the solid uppermost layer of the mantle
• molten liquid rock

What term best describes plate boundaries?

• cookie crumbles
• thin lines
• unobservable
• wide regions

Which theory of plate movement occurs at the mid ocean ridge?

• convection
• ridge push
• slab pull