The Restless Earth

Question 1

How thick is the earths crust?

Answer 1

60-70km, 5-8km

Question 2

What temperature is the earths mantle?

Answer 2

400•C - 2000•C

Question 3

What state is the earths mantle?

Answer 3

Semi-solid

Question 4

What temperature is the earths outer core?

Answer 4

2000-2500

Question 5

What state is the earths outer core?

Answer 5

Liquid

Question 6

What temperature is the earth inner core?

Answer 6

2500-3000

Question 7

What state is the earth inner core?

Answer 7

Solid

Question 8

What is the earth inner core made of?

Answer 8

Iron and nickel

Question 9

What are the thinnest and thickest layers in the earths structure?

Answer 9

Thinnest- crust

Thickest- mantle

Question 10

Name the 8 plate boundaries

Answer 10

African

Antarctic
Eurasian
Nazra
Indo- Australian
North-American
South-American
Pacific

Question 11

Name the 3 types of plate boundaries

Answer 11

Constructive (divergent)

Destructive (convergent)
Conservative (wrench/tear/fault)

Question 12

Formation of constructive plate boundaries

Answer 12

1. Convection current pulls plates apart
2. Mantle rises through plates
3. Magma solidifies and makes new material
4. Underwater volcano/oceanic ridge formed

Question 13

Two types of destructive plate boundary

Answer 13

1. Subduction
2. Collision

Question 14

Formation of subduction plate boundaries

Answer 14

1. Oceanic plate is more sense so it sinks below continental plate
2. Oceanic plate melts making it’s less dense than the continental plate
3. Oceanic plate rises and creates volcano

Question 15

Formation of collision plate boundaries

Answer 15

1. Two plates of same density are pulled together by convection current
2. They collide and push up to form fold mountains

Question 16

Conservative plate boundaries

Answer 16

1. Two plates slide past each other at different speeds (same or different direction)
2. Friction created
3. Plates finally jerk past each other release tension and energy

Question 17

3 types of volcanoes

Answer 17

1. Shield volcano
2. Dome volcano
3. Composite volcano

Question 18

Shield volcanoes

Answer 18

• gently sloping sides
• low silica content
• runny lava
• erupt frequently but gently
• oceanic ridges

Question 19

Dome volcanoes

Answer 19

• steep, convex sides
• high silica content
• viscous and acidic lava
• erupt less frequently and violently

Question 20

Composite volcano

Answer 20

• have a secondary/parasitic vent
• alternate layers of ash and lava
• look like come volcano
• when main vent is blocked a secondary develops
• erupt v. infrequently but v. violently

Question 21

How to monitor/predict volcanoes

Answer 21

• testing gases
• measurement of land
• tutmeters measure changes in angles
• flow can be predicted
• robots can be sent into volcanoes to test soil/rock changes

Question 22

Super volcanoes

Answer 22

• much bigger
• emit 1000km^3 of material
• appear as large depressions/calderas

Question 23

Formation of super volcanoes

Answer 23

1. Rising magma can’t escape
2. Large bulge forms
3. Cracks on surface of bugle emit gas
4. Roof of magma chamber collapses and large depression forms

Question 24

Earthquakes

Answer 24

Occur when plates move at major fault lines

Question 25

Which plate boundaries do earthquakes occur at

Answer 25

All 4 types, mainly destructive+constructive plate boundaries

Question 26

What scales are used to measure earthquakes

Answer 26

Mercalli scale and Richter scale

Question 27

Name of device which ensures magnitude of earthquake

Answer 27

Seismograph

Question 28

Richter scale is a _____ scale

Answer 28

Logarithmic

Question 29

Focus point

Answer 29

Where ye rock moves and seismic waves are produced

Question 30

Epicentre

Answer 30

Directly above the focus point on the earths surface

Question 31

6 variables which determine earthquake damage

Answer 31

1 size 2 emergency services 3 buildings 4 time of day 5 education 6 physical landscape

Question 32

Monitoring and predicting earthquakes

Answer 32

- geologists measure earths activity around the world - tremors plotted by geological surveys on major fault lines

Question 33

Preparing for earthquakes

Answer 33

- education in MDCs - houses interiorly designed to withstand earthquakes - buildings built to withstand earthquakes (low centre of gravity) - emergency services well prepared

Question 34

Tsunamis

Answer 34

Total waves which are triggered by an underwater earthquake

Question 35

What speed to tsunamis travel at?

Answer 35

400-600 kph

Question 36

What's the primary and secondary effect of a tsunami?

Answer 36

Primary- displacement of oceanic plate Secondary- displacement if water

Question 37

How far will 2 crests be from each other in a tsunami?

Answer 37

Regular wave- 100m Tsunami- 200km