2.4 Sea floor spreading and subduction

The OLDEST seafloor is located? 

• Closest to the mid-ocean ridge
• Farthest from the mid-ocean ridge

True or False : Sea-floor Spreading adds new material to the ocean floor?

• True
• False

What happens when Subduction occurs?

• Parts of the crust fall into the mantle
• Parts of the crust fall into the core
• Parts of the crust fall into space
• None of these

True or false : Deep-Ocean Trenches are underwater canyons?

• False
• True

What did scientists use to map the oceans floor?

• Echo-location
• Sonar
• Space Shuttles
• Animals

What is one piece of evidence of seafloor spreading? 

• scientist found animals at the bottom of the sea
• mountain rocks crashed into the ocean
• scientist found pillow shaped rocks like pillows

What process takes place at the trenches? 

• divergent boundaries
• subduction
• new crust is formed
• mountain ranges

New crust is always formed at the...

• mid-ocean ridge
• deep-ocean trench
• asthenosphere

If there are MORE mid-ocean ridges than subduction zones, what happens to the ocean?

• It gets larger
• It gets smaller
• It sinks

What is a divergent boundary? 

• two plates moving towards each other
• two plates rubbing side to side
• two plates moving away from each other
• happens in the lithosphere