Seafloor Spreading Essentials Concept Review

convection currents

seafloor spreading and plate tectonics theory is driven by this process occurring in the Earth's mantle

oceanic

Because of the process of subduction at trenches, this type of crust is younger than the other type (choose continental or oceanic crust is younger)

younger

EVIDENCE: The age of the seafloor at the mid-ocean ridge is (younger/older) than the age of the seafloor farther from the mid-ocean ridge

older

EVIDENCE: The age of the seafloor farther away from the mid-ocean ridge is (younger/older) than the age of the seafloor closer to the mid-ocean ridge.

magnetic field

EVIDENCE: The reversal of Earth's _____________ is recorded in the pattern of the seafloor

magma

EVIDENCE: This material has been observed erupting along mid-ocean ridges, forming new seafloor.

younger

Since old seafloor subducts into trenches the ocean crust is (younger/older) than continental crust

growing

The Atlantic ocean, with the mid-Atlantic ridge and just a few small trenches, is (growing/shrinking)

shrinking

The Pacific Ocean with numerous trenches along the Ring of Fire is (growing/shrinking)

granite

continental crust is primarily made of this type of igneous rock

more dense

oceanic crust subducts under continental crust because it is (more dense or less dense?)

seafloor spreading

process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.

subduction

process where denser oceanic crust sinks under another plate back into the mantle at a trench.

magnetic stripes

The pattern of these on the seafloor is identical on either side of the ridge.

continental drift

The process of seafloor spreading helped support/prove what theory?

seafloor spreading

What is the process occurring in this diagram?

subduction

What process is occurring in this picture where the ocean crust is meeting the continental crust?

mid-ocean ridge

long underwater mountain chains where new ocean crust is formed

trench

oceanic crust is "recycled" in the mantle when it subducts at this feature

basalt

oceanic crust is primarily made of this type of igneous rock

magma

what is the orange/red material in the diagram?

convection

what process is occurring in the mantle in this diagram?