Plate tectonics

Plate tectonics

The earth is divided into different "plates" that move with heat power

Crust and part of the upper mantle

The planets are all of the ....

Lithospheric plate

Tectonic plates are also called....

Asthenosphere

Directly below lithosphere mantle material

Ocean crust and continental crust

What are the 2 different types of crust?

Continental crust

Less dense (so it floats higher) and made up of granitic

Ocean crust

More dense and made up of basalt

Float

Both are less dense than the mantle so they ...

Type

The ... of tectonic plate impacts its density

Continental and ocean

Some tectonics plates are made up of both ...

Plate motion

Explains the movement of plates (Moves part of the mantle)

Convection cells

As heat from the mantle increases, so does it's buoyancy. It starts to rise to the surface, causing the rocks to expand. When it reaches the surface, it cools and lowers back into the earth

Slab pull

One plate is moving underneath another to the mantle. The more deeper it gets, the more faster it gets, causing it to break apart of the other plate

Divergent, covergent, and transform

What are the different plate boundaries?

Divergent

As the plates start to spread to spread (bc of density) apart (bc of the heat), a rift appears and if spreading continues on land, it would fill with water (ocean mostly)

Linear sea

A sea between plates that looks like they were one before

Mid-ocean ridges or spreading centers

Under the sea, the spreading

extensive

Mid-ocean ridges have the most ... chain of mountains on earth

Fissures

Magma fills ... in seafloor and solidifies (cause of water)

Rapid

Little erupts onto he seafloor as lava unless spreading is very ...

Convergent plate boundaries

Where 2 plates smashes together (crash)

Ocean-continent, ocean-ocean, continent-continent

What are the 3 types of convergent plate boundaries?

Oceanic-continental convergence

- Have volcanoes and trenches

- Ocean plate is sub ducted

- Continental arcs generated

- Explosive andesitic volcanic eruptions

Density

The plate with the most...(the oceanic) is the one that always submerges

Oceaanic-oceanic convergence

-Denser plate is subducted

-Volcanoes makes steam mounts

- Island arcs made by volcanoes

- Deeper trenches generated

Continental-continental

(rare)

- Subduction ceases

- Tall mountains uplift

- When they collide, mountains are formed bc the crust is very buoyant and they have no where to go but up

Transform boundaries

Plates that are moving along each other (across or together) (happens when the spreading of the plates varies) creates shallow but strong earthquakes

segments

In transformation, ... of plates slide past each other