Year 9 Term Test

Question 1

what’s the innermost layer of the earth?

Answer 1

The inner core

Question 2

What’s the inner core made of?

Answer 2

Solid iron and nickel

Question 3

Which is the densest layer of the earth?

Answer 3

The inner core

Question 4

Temperature of inner core?

Answer 4

6000C

Question 5

How thick is the inner core?

Answer 5

1260km thick

Question 6

How thick is the outer core?

Answer 6

2200km thick

Question 7

What’s the outer core made of?

Answer 7

Molten iron and nickel

Question 8

Which is denser, the outer core or mantle?

Answer 8

Outer core

Question 9

How thick is the mantle

Answer 9

2900km thick

Question 10

The mantle is denser than the crust. True or false?

Answer 10

True

Question 11

What’s the difference between the upper and lower mantle?

Answer 11

The upper mantle is rigid and the lower mantle is semi-molten and the zone of convection currents

Question 12

What’s the thinnest and densest layer of the earth?

Answer 12

The crust

Question 13

What makes up the lithosphere?

Answer 13

Crust and rigid upper mantle

Question 14

How thick is the continental crust?

Answer 14

30-50km thick

Question 15

What’s the continental crust made from?

Answer 15

Granite

Question 16

What’s the difference between the continental crust and the oceanic crust?

Answer 16

Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite. The low density of continental crust causes it to “float” high atop the viscous mantle, forming dry land.

Question 17

Where do destructive margins occur?

Answer 17

When two plates, one made of oceanic crust and one made of continental crust are converging.

Question 18

What happens when oceanic and continental plates meet?

Answer 18

The continental plate dives beneath the oceanic plate because it is denser. This is subduction.

Question 19

How do fold mountains occur?

Answer 19

They occur when the continental plate buckles upwards and creates a range of fold mountains.

Question 20

How do earthquakes and volcanoes occur?

Answer 20

They occur when pressure is released in a sudden slippage of the plates, resulting in a powerful earthquake. The friction also can generate a lot of heat causing the descending crust to melt which creates extra magma which rises to the surface through cracks in the rock resulting in violent volcanic eruptions.

Question 21

What is a constructive margin?

Answer 21

Two plates are diverging above the upward plume of a convection cell. Magma rises through the gap between the two plates, resulting in a volcanoes.

Question 22

Where are a lot of constructive margins?

Answer 22

Along the mid Atlantic ridge

Question 23

Name of volcano:

Answer 23

Eyjafjallajokull

Question 24

What’s a collision margin?

Answer 24

They occur when two plates made of continental crust converge. Because they are the same desnseness so subduction does not occur. Therefore the plates simply buckle and form fold mountains. They only cause earthquakes not volcanoes.

Question 25

What’s a conservative margin?

Answer 25

When two plates move alongside one another in opposite directions or in the same direction. Friction can cause the two plates to stuck and pressure builds up. When they slip it causes an earthquake. No volcanoes though as there is no rising magma.

Question 26

Epicentre:

Answer 26

The point on the earths surface directly above the focus, shaking here will be strongest

Question 27

Focus:

Answer 27

Point underground where plates slip and from where seismic waves radiate outwards

Question 28

Aftershock:

Answer 28

Smaller earthquakes following the earthquake as the plates slip to settle into their new configuration.

Question 29

Seismic waves:

Answer 29

Energy that radiates out from the focus and causes the ground to shake. Primary waves compress the ground whilst secondary waves shake it from side to side.

Question 30

Fault line:

Answer 30

A fracture in the rock at a plate margin when pressure builds up if the moving plates stick

Question 31

What does the Richter scale do?

Answer 31

It assesses the amount of energy released by the earthquake, and the intensity of shaking. It’s a logarithmic scale which means that every point you go up on the scale sees a 30-fold increase in energy rea,eased.

Question 32

What does the mercalli scale do?

Answer 32

It assesses at the impacts of an earthquake by looking at things like the structural damage to buildings. This is more subjective but useful for groups such as aid workers.

Question 33

Stratovolcano:

Answer 33

Ash clouds, infrequent explosive eruptions, acidic lava, 800C, destructive margins, ash falls most thickly around the volcanic vent, narrow base, steep sides, high viscosity, gets stuck in the vents leading up to building of pressure.

Question 34

Shield volcano:

Answer 34

1200C, basic lava, frequent gentle eruptions, faster moving lava, hot, low viscosity, lava flows far from the vent before solidifying, instructive margins, broad base, gentle slopes.