Earths structure

Question 1

What are the different layers of the earth?

Answer 1

Inner core
Outer core
Mantle
Crust

Make sure you can draw a diagram.

Question 2

1. What is the inner core?
2. What is the outer core?
3. What is the mantle?
4. What is the crust?

Answer 2

1. Solid ball, iron and nickel alloy
2. Fluid layer of iron and nickel
3. Heavy, hot soft rock both solid and liquid.
4. Solid thick rock.

Question 3

What are the two types of earths crust?

Answer 3

Oceanic crust

Continental crust

Question 4

What is oceanic crust?

Answer 4

Denser so can sink into mantle.
5-10km thick - relatively newer and thin.
Mainly basalt.
Can be made and destroyed.

Question 5

What is continental crust?

Answer 5

Approx 30km thick - lighter, thicker, older.
Can’t sink because less dense.
Mainly granite.
Can’t be made or destroyed.

Question 6

What are the plate movement theory’s?

Answer 6

Convection current theory
Slab pull
Rigid push

Question 7

What is convection current theory?

Answer 7

The earth’s core is the heat source.
As the heat rises it creates convection currents in the mantle.
The currents cause plates to move together or apart.

Question 8

Explain slab pull/rigid push theory?

Answer 8

Slab pull - Heavy old lithospheric plates dragged into mantle.
Becomes part of mantle.
Happens at destructive plate margins.

Rigid push - lighter newer plates pushed allowing magma from mantle to rise.
Magma forms new crust at constructive plate margins.

Question 9

What are the major plates and faults of the earth’s crust.

Answer 9

Pacific plate
North American plate 
Nazca plate
South American plate 
Caribbean plate
Eurasian plate 
Indo-Australian plate 
Philippine plate 
Antarctic plate
African plate
Mid-Atlantic ridge 
San Andreas fault