1.7 tectonics

what are the layers in the earth

crust

mantle

outer core

inner core

what is the characteristics of the crust

5-70km thick

made up of oceanic rock and continental rock

what is the mantle split up into

upper mantle

lower mantle

asthenosphere

what is the characteristics of the upper mantle

solid but rigid

1500 degrees

what is the characteristics of the lower mantle

solid

3000 degrees

what is the characteristics of the asthenosphere layer.

semi molten

1400-3000 degrees

high density.

what is the characteristics of the outer core

liquid iron and nickel

4000-6000 degrees

generates earths magnetic fields

what is the characteristics of the inner core

solid iron and nickel

6000 degrees

highest density

where does radioactive decay occur and what does it make

it happens in the mantle and creates heat

what is convection current

circular movement of mantle rising making the tectonic plates move.

how does convection current work

mantle gets heated and it rises, becomes less dense

near the crust it cools and sinks becoming more denser

when the mantle sinks it moves sideways against the tectonic plates

this makes tectonic plates also move when the mantle moves sideways.

what are the four things that can occur when convection currents happen

divergent (constructive)

convergent (destructive)

conservative

collision

what is divergent

plates move apart forming shield volcanoes

what is convergent

oceanic and continental rock collides making the oceanic rock sink and melt into magna due to hot temperatures in the mantle and when it rises it will cause volcanoes to erupt.

what is conservative

when plates are in contact but move in opposite directions creating lots of tension and heat, once released it will create very strong earthquakes.

what is collision

when two continental rock collide with each other forming fold mountains.