Tectonic hazards

Question 1

Cross section of the Earth


Answer 1

Crust, mantle, outer core, inner core

Question 2

What is the mantle?


Answer 2

Made of semi-molten rock, magma
Thickest section - 2900km
Magnesium and iron

Question 3

What is the inner core?


Answer 3

Solid layer of iron and nickel
Temperature of 5500 oC

Question 4

What is the outer core?


Answer 4

Liquid layer of the Earth’s core, made of iron and nickel

Question 5

Characteristics of continental plates


Answer 5

Older
Less dense
Can’t sink

Question 6

Characteristics of oceanic plates


Answer 6

Younger
Very dense
Can sink

Question 7

Explain the theory of convection currents


Answer 7

Magma near the outer core is heated. As the magma warms, it expands and becomes less dense. The less dense magma then starts to rise towards the crust. As the magma nears the crust, it begins to cool. The cooling magma becomes denser and begins to sink. The rising and falling magma creates circular currents with the mantle. These currents create friction with the crust above and causes it to move. These are known as convection currents.

Question 8

Explain the theory of ridge push


Answer 8

Magma rises as the plates move apart. Magma cools to form new plate material. As it cools it becomes denser and slides down away from the ridge. This causes tectonic plates to move away from each other. Occurs at constructive plate margins.

Question 9

Explain the theory of slab pull


Answer 9

Denser plate sinks back into the mantle under the influence of gravity. It pulls the rest of the plate along behind it.

Question 10

Which plate margins are earthquakes found at?


Answer 10

All 3 (constructive, destructive, conservative)

Question 11

Which plate margins are volcanoes found at?


Answer 11

Constructive and destructive

Question 12

Explain the constructive plate boundary


Answer 12

The plates move away from each other. When this happens, the magma from the mantle rises up and cools to make new land in the form of a shield volcano. Ridge push occurs. The movement of plates over the mantle can cause earthquakes. Ridges can form.

Question 13

Explain the destructive plate boundary

Answer 13

The dense oceanic plate is subducted under the lighter continental plate into the mantle. Slab pull occurs. Friction causes melting of the oceanic plate and may trigger earthquakes. Destructive plates cause both volcanoes and earthquakes.

Question 14

Landforms formed at constructive boundaries


Answer 14

Shield volcanoes and ocean ridges

Question 15

Landforms formed at destructive boundaries


Answer 15

Composite volcanoes, oceanic trenches

Question 16

Explain the conservative plate boundary


Answer 16

As the plates move, friction occurs and plates become stuck. Pressure builds up because the plates are still trying to move. When the pressure is released, it sends out a huge amount of energy causing an earthquake.

Question 17

How do plates move at constructive margins?


Answer 17

Away from each other

Question 18

How do plates moves at destructive margins?


Answer 18

Towards each other

Question 19

How do plates move at conservative margins?


Answer 19

Move past each other in same or opposite direction but at different speeds

Question 20

Landforms at conservative margins


Answer 20

Fault lines (San Andreas fault line)

Question 21

How many killed in L’Aquila earthquake?


Answer 21

308

Question 22

How many killed in Gorka, Nepal earthquake?


Answer 22

8,841

Question 23

Economic damage of L’Aquila


Answer 23

$11,400 million in damage

Question 24

Economic damage of Gorka


Answer 24

$5 billion damage

Question 25

Primary effects of L'Aquila earthquake 


Answer 25

308 killed and 1500 injured $11,000 million in damage 15,000 buildings collapsed including San Salvatore hospital and L'Aquila university

Question 26

Secondary effects of L'Aquila earthquake


Answer 26

Landslides damaged housing and transport House prices and rent increased Some of city cordoned off, reducing business. Burst water pipeline caused a mudflow.

Question 27

Immediate responses to the L'Aquila earthquake


Answer 27

Free mobile calls 10,000 sheltered at hotels, 40,000 tents given. $550 million raised from EU Solidarity Fund . Dog units searched for survivors.

Question 28

Long-term responses to the L'Aquila earthquake


Answer 28

Torch-lit procession with Catholic mass every year. No taxes for residents during 2010. Students university fees waived and received free public transport.

Question 29

When was the L'Aquila earthquake, Italy?


Answer 29

April 2009

Question 30

When was the Gorka earthquake, Nepal?


Answer 30

April 2015

Question 31

Primary effects of the Nepal Earthquake.


Answer 31

8,841 died. 1 million made homeless UNESCO heritage site destroyed $5 billion damage. International airport congested as aid arrived. 7,000 schools and 26 hospitals destroyed

Question 32

Secondary effects of the Nepal earthquake


Answer 32

Tourism employment and income declined. Landslides and avalanches on Mount Everest killed 19 people. Landslide blocked river so people evacuated in case of flooding. Blocked roads slowed aid. Rice seed ruined, food shortages and income loss.

Question 33

Immediate responses to the Nepal earthquake


Answer 33

International help requested. 500,000 tents provided. Rescues from avalanches on Mount Everest made by helicopter. UN and World Health organisation sent medical supplies to the worst affected districts. Field hospitals set up.

Question 34

Long-term responses to the Nepal earthquake


Answer 34

$247 million aid money committed to recovery. Lakes and river valleys cleared of landslide material to avoid flooding. Stricter building controls enforced. New trekking routes on Mount Everest opened.

Question 35

Social reasons people live at risk from tectonic hazards


Answer 35

People want to stay near families and friends Threat isn't great enough People are confident that the buildings will keep them safe

Question 36

Economic reasons people live at risk from tectonic hazards


Answer 36

Geothermal energy provides energy for area. Nutrient-rich soils helps agriculture Mining provides energy and income Tourism creates jobs and provides income Cheaper to stay than to move

Question 37

How can volcanic eruptions be monitored?


Answer 37

Changes in shape of ground using tiltmeters and GPS satellites. Radon and sulphur gas can be measured using gas-trapping bottles Thermal heat sensors, ground surface and river temperatures Earthquakes near magma chamber using seismometers

Question 38

How can volcanic eruptions be predicted?


Answer 38

Easier to predict than earthquakes as they give warning signals before erupting.

Question 39

How can people be protected against volcanic eruptions?


Answer 39

Buildings can't be designed to completely protect against eruption. Evacuation issued by authorities.

Question 40

How can people plan for volcanic eruption?


Answer 40

Evacuation Exclusion zones Education First-aid training

Question 41

How can earthquakes be monitored?


Answer 41

Foreshocks using seismometers and GPS. Radon using radon detection devices. Harder to monitor than volcanoes

Question 42

How can earthquakes be predicted?


Answer 42

They can't

Question 43

How can people be protected against earthquakes?


Answer 43

Building infrastructure - foundations with rubber shock absorbers Sea walls in case of tsunamis

Question 44

How can people plan for earthquakes?


Answer 44

Practice drills Preparing emergency supplies Knowing location of evacuation centres Securing furniture