Paper 1 - Hazardous Earth (Techtonics) Flashcards
what are the 2 types of crusts
oceanic and continental
continental crust facts
- made of thick granite
- low density
- forms over the land
oceanic crust facts
- under the oceans
- made of basalt
- high density
- 6-8km deep (thin)
lithosphere
uppermost layer of the earth - it includes the top of the mantle and the crust
—> it is cool and brittle
asthenosphere
part of the earth’s mantle below lithosphere
—> it is hot, semi-molten layer
techtonic plates
the earth’s surface is broken into large pieces
layers of the earth
- crust
- mantle
- outer core
- inner core
convection current
this occurs in the mantle and is the rising, spread, and sinking of magma
how do plates move - convection current
- hot air rises
- it looses heat and cools down
- it sinks back down to be reheated
- the magma and crust create friction which causes the plates to move
continental drift
250 million years ago, the land masses of earth were clustered into one super continent called Pangea, as millions of years passed, Pangea broke apart and large pieces of land slowly moved away into the continents as we know them today
pieces of evidence for continental drift
- the Meosuarus
- continental jigsaw
- coal deposits
what types of crusts are found at divergent plate boundaries
- oceanic
- oceanic
what types of crusts are found at convergent plate boundaries
- oceanic
- continental
what types of crusts are found at collision plate boundaries
- continental
- continental
what types of crusts are found at conservative plate boundaries
- continental
- continental
types of plate boundaries
- divergent
- convergent
- collision
- conservative
movement of divergent plate boundaries
<— —> (plates move apart)
movement of convergent plate boundaries
one plate subducts under the other
movement of collision plate boundaries
—> <— (plates collide)
movement of conservative plate boundaries
plates slide past each other
hotspot volcano
an area of the Earth’s mantle from which hot plumes rise upward, forming volcanoes on the overlying crust