8.3 Review

What are the three major hypotheses that describe how plate movements are caused?

• Tectonic, magnetic, and seismic
• Convection currents, push ridge, and slab pull
• Asthenosphere, lithosphere, and mantle
• Earthquakes, volcanoes, and tsunamis

What provides the plates with a surface on which they can move?

• Crust
• Asthenosphere
• Outer core
• Troposphere

Which layer in the upper mantle is pliable (flexible)?

• Lithosphere
• Asthenosphere
• Outer core
• Mesosphere

Heat transfer through the mantle is known as:

• Plate tectonics
• Mantle convection
• Crustal uplift
• Basaltic eruption

What causes the lithospheric plate to move in mantle convection?

• Only the upwelling of cooler rocks
• Only the downwelling of hotter rocks
• Circular movement of magma
• Subduction at the plate boundary

Ridge push can be more accurately described as:

• Gravitational sliding
• Ridge pull
• Seafloor rising
• Subduction sinking

What force is exerted by cooling subsiding rock on the spreading lithospheric plates at a mid-ocean ridge?

• Ridge push
• Slab pull
• Mantle convection
• Crustal deformation

What force is exerted by the sinking edge of the subducting plate on the rest of the plate at a subduction boundary?

• Ridge push
• Slab pull
• Mantle convection
• Crustal deformation

Which of the three hypotheses, mantle convection, ridge push, or slab pull, is considered to be the strongest factor by many scientists?

• Mantle convection
• Ridge push
• Slab pull
• They are all equally important