plate boundaries/ movement

Question 1

what are the 2 types of crust

Answer 1

oceanic and continental

Question 2

what is an oceanic crust

Answer 2

a thin layer of heavy rock

Question 3

what is a continental crust

Answer 3

a thick layer of lighter crust

Question 4

constructive plate boundary

Answer 4

two plates move apart, magma rises to fill the gap. this causes volcanoes with gentle slopes and a wide base(sheild volcano)

Question 5

destructive plate boundary

Answer 5

oceanic and continental plate meet. the ocenic is heavier so it sinks. the plate then begins to melt and becomes magma. this breaks through the crust to form explosive volcanoes.

Question 6

destructive collision plate boundary

Answer 6

two continental plates meet and as they are the same weight neither sinks. this cause the material between to buckle and rise forming fold mountains

Question 7

conservative plate boundary

Answer 7

two plates dont directly collide but slide past each other along a fault. as the plates slide past eachother they get stuck causing pressure to build and the plate breaks causing powerful and frequent earthquakes.

Question 8

how do plates move (4 steps)

Answer 8

1. the plates float on top of the mantle and move because of convection currents.
2. the liquid mantle is heated, rises, cools and sinks in a continous cycle known as a convection current.
3. when convection currents reach the surface they cause the plates to move.
4. this movement of the plates is what makes the earths crust unstable.

Question 9

what is a continental drift

Answer 9

the movement of tectonic plates across the earths surface very slowly through geological time

Question 10

what are the 4 layers of the earth

Answer 10

inner core, outer core, mantle and crust