Seafloor Spreading

In the Atlantic ocean, where is the youngest seafloor located?

• Towards the edges, near the eastern and western continents
• Towards the middle of the ocean at the mid-ocean ridge

• Towards the north and south poles
• Young seafloor is located randomly throughout the ocean

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NGSS.MS-ESS2-3

How do scientists figure out the age of the seafloor?

• They research it from ancient sea maps that trading vessels would use in the 1700s
• They use the moon phases and eclipses to calculate the age
• They use seismographs and the depth as well as location of earthquakes to calculate the age
• They take drill ships to many locations in the oceans and collect, then date, rock samples. 

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NGSS.MS-ESS1-4

The average density of continental crust is 2.8 g/cm³ and the average density of oceanic crusts is 3.2 g/cm³. If these two plates came together, what would happen?

• The two plates would push apart and form a rift zone.

• The oceanic plate would rise up over the continental plate.

• The oceanic plate would sink under the continental plate.

• The two plates would meet head on and rise up to form mountains.

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NGSS.MS-ESS2-2

What process is occurring at Z?

• Convection currents       
•  Subduction 
• Two plates moving apart
• New ocean floor forming

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NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

Why does the ocean floor sink beneath the continent at Z?

• The ocean floor is less dense than the continent.
• The ocean floor is more dense than the continent.
• The ocean floor is moving faster than the continent.
• The ocean floor is moving slower than the continent.

Tags

NGSS.MS-ESS2-2

What are the two types of crust?

• continental and oceanic
• ocean and basin
• lower and upper
• thick and thin

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

Tags

NGSS.MS-ESS2-3

What type of evidence was NOT used by Alfred Wegener to support his continental drift hypothesis?

• evidence from landforms
• evidence from fossils
• evidence from human remains
• evidence from climate

The process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle is known as

• convection
• continental drift
• subduction
• conduction

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NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

The image shows a mid ocean ridge. What is an important feature of seafloor spreading?

• Mid ocean ridges only occur at convergent boundaries.

• The convection currents in the core drive the plates apart.

• As the plates pull apart, the lava rises to form new crust.

Tags

NGSS.MS-ESS2-3