Seafloor Spreading, Subduction & Continental Drift

Mid-ocean ridges are:

• valleys along the ocean floor

• underwater mountain chains with a valley that runs through the middle

• a trench on the ocean floor- some of the deepest places on Earth

• a canyon on the ocean floor formed due to weathering and erosion

Tags

NGSS.MS-ESS2-3

Deep-ocean trenches are:

• depressions on the ocean floor that are deeper than they are wide

• a canyon on the ocean floor formed due to weathering and erosion

• an underwater mountain chain with a valley at the center

• volcanic islands formed from subduction

Subduction is the process where:

• new oceanic crust is formed

• oceanic crust thickens due to solidification of magma

• one plate is pushed down into the mantle beneath another plate

• two plates push together forming a mountain

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

Select all that are true about oceanic crust

• older crust is formed close to the mid-ocean ridge

• older crust is found farther away from the mid-ocean ridge

• older oceanic crust is more dense

• older oceanic crust is less dense

• oceanic crust is made of the igneous rock granite

Where (at what landform) is oceanic crust recycled back into the mantle?

• mid-ocean ridge

• deep-ocean trench

• seafloor spreading

• subduction

Tags

NGSS.MS-ESS2-1

Subduction of oceanic crust always leads to the formation of this on the non subducting plate:

• new oceanic crust

• a mid-ocean ridge

• vocalano

• a rift valley

OCeanic crust closer to the MOR is:

• te same density no matter location to the MOR

• less dense that rocks farther away

• more dense than rocks farther away

Which two pieces of evidence supports the theory of seafloor spreading?

• Iron minerals have been arranged in specific directions based on the Earth's magnetic field

• Older rock samples have been found furthest from mid-ocean ridges and closest to continental crust while younger rock has been found nearest to mid-ocean ridges.

• Rising magma has been pinpointed toward the outer edges of oceanic crust

• Dispersed fossil remains of the Mosasaur have been located across the ocean on two different continents.

Tags

NGSS.MS-ESS2-3

What happens to older oceanic crust as new rock is formed during seafloor spreading?

• it forms granite

• it is pushed away from the mid-ocean ridge

• it gets pulled under the mid-ocean ridge

• it forms new volcanos on the ocean floor

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

Currently, Earth's geographic north pole is its magnetic ________.

• north

• south

• east

• west