Volcanoes

Question 1

What are the three layers that make up the Earth

Answer 1

The three layers that make up the earth are the crust, the mantle and the core

Question 2

What is the crust

Answer 2

The crust is the layer we live on. Its a thin skin of rock around the Earth

Question 3

How big is the crust

Answer 3

Its 8 - 65 km thick

Question 4

What’s the difference between the oceanic plate and the continental plate

Answer 4

The oceanic plate is 6-8 km thin, while the continental plate is up to 70km thick

Question 5

What is the mantle

Answer 5

The mantle is heavy rock that has a size of about half the Earth. The upper mantle is hard, but the lower part of the mantle is hot and soft

Question 6

What is the core

Answer 6

The core is made up of two parts. The outer core which is liquid and the inner which is solid. Both are made up of iron and some nickel

Question 7

Where do volcanoes and earthquakes occur?

Answer 7

Earthquakes and volcanoes occur in plate boundaries

Question 8

What are plate boundaries?

Answer 8

Plate boundaries are the lines were plates meet

Question 9

Name three possible ways in which plates move

Answer 9

Three ways in which plates move are, pull-apart plates, push-together plates, slide-past plates

Question 10

What’s another name for “pull-apart” plates

Answer 10

Another name for pull-apart plates is divergent

Question 11

What’s another name for “push-together” plates

Answer 11

Another name for “push-together” plates is convergent

Question 12

Why do plates move

Answer 12

Plates move because of convection currents. The high temperature in the core warms the liquid in the mantle, causing it to rise upwards. It eventually meets the crust, which cools it down, causing it to sink downwards. This process is repeated over and over again in a circular manner, making the flow of liquid rock in the convection currents move the tectonic plates slowly

Question 13

Name 4 types of plate boundaries

Answer 13

Destructive plate boundaries, Constructive plate boundaries, Collision plate boundaries, Conservative plate boundaries

Question 14

What is a destructive plate boundary

Answer 14

A destructive plate boundary is a convergent boundary where one oceanic plate and one continental plate move together. The oceanic plate moves under the continental plate, as it has a greater density. This process is called subduction

Question 15

How do destructive plate boundaries cause earthquakes

Answer 15

Destructive boundaries cause earthquakes by the friction of the plates. As the oceanic plate is push under the continental, their plates rub together, creating earthquakes

Question 16

How do destructive boundaries cause volcanoes

Answer 16

As the oceanic plate is pushed under the continental, it meets with the mantle, causing to melt. Lighter elements of the plate rise as magma, forming volcanoes when it reaches the surface

Question 17

What is a constructive plate boundary

Answer 17

A constructive plate boundary occurs when two plates move apart. Its a divergent boundary. As the two plates are pulled apart by the convection currents, magma rises between the plates. It turns into basalt that forms a new ocean floor. The ocean floor gets wider by 2cm every year

Question 18

What is a collision boundary

Answer 18

A collision boundary is when two continental plates move together. Because of the low density of both, neither is pushed downwards. The crust is pushed up and folded to form mountains. The movement of the rock causes earthquakes.

Question 19

What is a conservative plate boundary

Answer 19

A conservative boundary is when two plates slide past each other. It can create earthquakes, as part of the plates get stuck and then lurch free

Question 20

What is magma

Answer 20

Magma is molten rock underneath the surface of the earth

Question 21

What is lava

Answer 21

Lava is molten rock that has broken through the surface of the earth

Question 22

What are volcanoes

Answer 22

Volcanoes are vents in the ground that allow magma to come out from deep inside the Earth

Question 23

What are composite volcanoes

Answer 23

Composite volcanoes are volcanoes which are made up from lava and ash

Question 24

What is a magma chamber

Answer 24

A magma chamber is a store of molten rock deep inside the earth

Question 25

What is a crater

Answer 25

A crater is a funnel-shaped hole at the top of a volcano from where lava comes out

Question 26

What are secondary cones

Answer 26

Secondary cones form if the main vent is blocked and magma must come to the surface from another way

Question 27

What comes out when a volcano erupts

Answer 27

After a volcano erupts, lava, ash and volcanic bombs come out

Question 28

Name 4 types of volcanoes

Answer 28

Composite volcanoes, lava volcanoes, lava volcanoes and ash volcanoes

Question 29

What is an ash volcano

Answer 29

Volcanoes formed from ash that are usually steep sided

Question 30

What is a lava volcano

Answer 30

A volcano with thick, slow-flowing lava that hardens quickly, forming steep-sided volcanoes

Question 31

What is another type of a lava volcano

Answer 31

A volcano with runny, fast-flowing lava that moves and spreads easily. The volcanoes it forms have gently sloping sides

Question 32

What are active, dormant and extinct volcanoes

Answer 32

Active volcanoes are volcanoes that have erupted recently and are likely to erupt again Dormant volcanoes are volcanoes that have erupted in the last 2000 years but not recently Extinct volcanoes are volcanoes that will most probably never erupt again

Question 33

What are pyroclastic flows

Answer 33

A pyroclastic flow is a mixture of ash and hot gas erupted from a volcano. These clouds move with a speed of 300km/h and have a temperature of about 300 degrees

Question 34

What are natural hazards

Answer 34

Natural hazards are dangers to the people and the surroundings that are caused by volcanoes

Question 35

Give 3 examples of natural hazards

Answer 35

Floods, earthquakes, droughts

Question 36

Why do people live in volcanic areas

Answer 36

Ash and lava released by volcanoes turns into great soil after a few centuries and good weathering

Question 37

How does an earthquake occur

Answer 37

When two plates push towards each other, a lot of pressure builds up. When it gets too much, one of the rocks lurches upwards, resulting in the stored energy being released in seismic waves. Seismic waves travel through the earth, shaking everything around them

Question 38

What is the fault of an earthquake

Answer 38

A crack in the Earth's crust

Question 39

What is the focus of an earthquake

Answer 39

The focus is the point where the waves started

Question 40

What is the epicenter of an earthquake

Answer 40

The epicenter is the point directly above the focus

Question 41

How are earthquakes measured

Answer 41

Earthquakes are measured by the Richter scale

Question 42

What are the three P's

Answer 42

Predict, Protect, Prepare

Question 43

How can the three P's reduce the impacts of earthquakes

Answer 43

Predict: Even though it is very difficult to do, we could try to predict when an earthquake will occur. There are a few indications of that, such as the small fore-shocks before the main earthquake or simply the fact that an earthquake hasn't occurred in a long time Protect: Buildings should be designed in a way that complies with strict earthquake regulations, to prevent it from falling. This can help save many lives, as many of the people that die from an earthquake is due to the fact that the building they were in collapsed Prepare: The people should be prepared for what to do when an earthquake occurs. They should be educated, organized and ready for an earthquake to break out at any time