The Restless Earth

Question 0

Explain what happens at a constructive plate boundary

Answer 0

Convection currents drag two plates apart. There is a fissure created in the earths crust. Magma rises to fill the gap and solidifies to form new land.

Question 1

Explain what convection currents are?

Answer 1

1. Rock within the mantle within is heated by radioactive decay in the core
2. The rock becomes less dense and rises
3. As it moves away from its heat source, the rock cools, becomes more dense and sinks

Question 2

Give an example of a constructive plate boundary?

Answer 2

Eurasian and North American plates.

Question 3

Explain what happens at a conservative plate boundary?

Answer 3

Convection currents pull 2 plates past each other, however this movement is not smooth. This causes pressure to build, and the release of this is an earthquake.

Question 4

Give an example of a conservative plate boundary?

Answer 4

North American and Pacific plates.

Question 5

Explain what happens at a collision plate boundary?

Answer 5

Convection currents pull 2 continental plates together, and since neither can be subducted, they are forced upwards. This is not smooth, so earthquakes occur.

Question 6

Give an example of a collision plate boundary?

Answer 6

Nazca and South American plates.

Question 7

Explain what happens at a destructive plate boundary?

Answer 7

Convection currents pull an oceanic and a continental plate together. The oceanic plate is subducted, and this isn’t smooth causing earthquakes.

Question 8

Give an example of a destructive plate

boundary?

Answer 8

Pacific and Eurasian plates.

Question 9

What is an ocean trench?

Answer 9

A very deep area of sea, usually around 5,000-10,000m deep.

Question 10

What is a fold mountain?

Answer 10

A mountain made up if layers of sedimentary rock that have been crumpled up together to form sun lines and anticlines.

Question 11

Describe the formation of fold mountains?

Answer 11

1. Sediment is deposited in geosynclines
2. Compressed to form sedimentary rock
3. Plates move together to form anticlines and synclines

Question 12

Give background information in the Andes?

Answer 12

1. Western coast of South America
2. Colombia, Ecuador, Argentina, Peru, Bolivia and chile
3. Runs for 7,000km

Question 13

Farming in the Andes?

Answer 13

Subsistence farming. The most fertile a land is on the valley floor where they grow soya, maize, rice and cotton. Terraces are dug into the sides to stop leaching.

Question 14

Tourism in the Andes?

Answer 14

The inca trail covers 50km, and it is one of 23 world heritage sites.

Question 15

HEP in the Andes?

Answer 15

The yuncan dam in Peru dams rivers. There are many narrow rivers and it is mainly provided through melting snow.

Question 16

Mining in the Andes?

Answer 16

The yanacocha gold mine in Peru is the largest in the world.

Question 17

What are the disadvantages of living in a cold mountain area?

Answer 17

1. It is difficult to build infrastructure
2. Few industries and jobs
3. Risk of avalanches and earthquakes

Question 18

What is a volcano?

Answer 18

An extrusive feature formed by the accumulation of ash and lava during repeated eruptions.

Question 19

What are the characteristics of a shield volcano?

Answer 19

1. Gently sloping sides
2. Wide base
3. Solidified lava

Question 20

How are volcanoes monitored?

Answer 20

1. Seismometers are used to detect earthquakes
2. Thermal imaging cameras are used to detect heat
3. Gas samples can be taken to measure sulfur levels

Question 21

What are the primary effects of mount pinatubo?

Answer 21

1. Pyroclastic flows filled valley 660ft deep
2. A caldera that was 1.6 miles across was formed
3. An ash cloud covered 125,000km2 in darkness

Question 22

What are the secondary effects of mount pinatubo?

Answer 22

847 died
650,000 lost agriculture jobs
$700 million damage
1.2 homeless 
20,000 aeta highlanders displaced
800,000 livestock and poultry killed

Question 23

What were the short term responses to mount pinatubo?

Answer 23

250,000 evacuated
75,000 evacuated prior to eruption
3 evacuation zones
Evacuation camps built

Question 24

What were the long term responses to mount pinatubo?

Answer 24

159 evacuation centres were maintained 2 years after the eruption
Many people stayed in the U.S. rather than going back to the Philippines.

Question 25

What are the advantages of living in areas of tetonic activity?

Answer 25

Land is more fertile (Vesuvius is 8x more)
Lots of minerals for mining
Tourism (Vesuvius €25 million per year)

Question 26

What are the disadvantages of living in areas of tectonic activity?

Answer 26

People don’t have a choice yet their homes could be destroyed
Mining disasters due to sulfur
Death and injury

Question 27

What is an earthquake?

Answer 27

Vibrations under the earths crust that shake the grounds surface and are sudden without warning.

Question 28

What is the formation of a supervolcano?

Answer 28

1. Magma chamber forms over hotspots
2. Magma chamber grows and creates fissures in the crust
3. Pressure rises and gas and ash escape through the cracks
4. Magma chamber loses size, the ground sinks and creates a caldera.

Question 29

Give background information on Yellowstone?

Answer 29

It is in Yellowstone national park in North America.
The caldera is 55km by 72km.
The chamber is 80km by 40km by 8km.
Last erupted 630,000 years ago.

Question 30

What are the local effects of yellowstone?

Answer 30

1/3 die
Ash cloud would rise 40-50km into the atmosphere
10,000km2 land destroyed
15cm thick ash fall

Question 31

What are the likely worldwide effects of Yellowstone?

Answer 31

5 days after uk would see ash fall
Crops would fail
Europe, Asia and America would have constant snow for 3 years
Temps would fall by 12-15 degrees